There's no doubt, Ralph Fiennes portrayed Voldemort like an absolute boss in the Harry Potter movie franchise. For some, he is the awful, murderous wizard responsible for forever changing the wizarding world with his cult-like followers and absolute practices. For others, he is the evil genius who attempted world domination by whatever means necessary and went where almost no other wizard would (or could, morally). Regardless of how we feel about him, he is no doubt an absolute powerhouse in the Harry Potter franchise and the wizarding world (and could easily have his own spin-off). Where Harry, Hermione, and Ron represent the strength, kindness, and courage that Godrick Gryffindor himself would be proud of, Voldemort represents the necessary evil. He drives the story forward, making our wholesome wizards become more powerful, more savvy, and more united as a whole.
Of course, Voldemort is not such a force of nature on his own. Throughout the Harry Potter films and books, we get huge insights into his main power source: the Horcruxes. Undoubtedly, they gave him several opportunities to return to the world of the living, where he should’ve been resting six feet under time and time again. Although they aided him in his attempt at absolute power, immortality, and dictatorship, one could argue that they hurt him more than they helped in the long run. Indeed, here's why Voldermort would have lived longer if he hadn't relied on the Horcruxes.
The Horcruxes Left Him Vulnerable & Weak
Horcruxes are intended to make the user immortal (via Collider). A second or third chance at life, if you will. Although they did give Voldemort another chance to join the living after his curse against Harry Potter rebounded, they harmed him in the long run. In creating these Horcruxes, he gave the ability for other witches and wizards to destroy him without ever laying a finger on him. Voldemort was a powerful wizard, comparable only to Albus Dumbledore or Grindelwald, rocking an awesome wand and a sense for world domination. The chances of another wizard, or even a group of them, having the opportunity to kill Voldemort were slim to none. To get to Voldemort, you would first have to defeat his loyal Death Eaters, whom he seldom traveled without. These Death Eaters are well-trained, powerful in their own right, and viciously protective of their Dark Lord.
Even if you could accomplish eliminating the Death Eaters, you would still have to face Voldemort in a rigorous battle, continually dodging Avada Kadavra's and any other dark magic spells he wields. But having the opportunity to destroy him with no battle involved left Voldemort at a disadvantage and vulnerable. Additionally, with each Horcrux that was destroyed, Voldemort grew weaker, reducing his battle abilities and strength. This provided him with numerous, unfavorable situations. Finally, when one returns to physical form after dying, they need another wizard to aid them to completely restore them. Horcruxes do not provide you the ability to restore yourself on your own, leading to Voldemort relying on his followers or others in general to come back to life.
Harry Potter: The Accidental Horcrux
As we know, Harry Potter was perhaps Lord Voldemort's biggest mistake that he made along his journey to ultimate power. Although he never intended to make Harry a Horcrux, his mistake ultimately cost him his own life. Upon hearing the prophecy that a boy would be born who could destroy the Dark Lord, Voldemort set off to kill baby Harry. His soul was already so unstable from creating seven other Horcruxes throughout his life, that when the killing curse rebounded, it unintentionally put a part of Voldemort's soul into Harry. This led to Harry gaining priceless powers and insights into Lord Voldemort's plans and whereabouts.
This mistake gave Harry his unique ability to speak to snakes, an ability known as Parseltongue. Being able to speak Parseltongue, he was able to hear the Basilisk in Harry Potter and the Chamber of Secrets, leading to him finding the eponymous chamber and destroying his first Horcrux, the diary. Additionally, having the ability to speak Parseltongue also granted him access to opening Voldemort's locket and destroying another Horcrux in Harry Potter and the Deathly Hallows Part 1. This power alone lead to the destruction of two of the seven intentional Horcruxes. Furthermore, he gained insights into Lord Voldemort's mind. This power allowed him to see secret meetings, the whereabouts of the Dark Lord and gain information about planned attacks. Once Harry learned of this information, he used it to his full advantage, often knowing Voldemort's moves long before anyone else, making it nearly impossible to get close to him.
Finally, Harry was bestowed with the ultimate power: hearing Horcruxes. This ability was not only unique to Harry himself, but allowed him, with clues of course, to find each Horcrux with minimal complications and completely disintegrate them, leading to the demise of Voldemort. That task alone could have never been achieved by another wizard, making Harry the most deadly weapon Voldemort could've ever faced — and he made the weapon himself. If Voldemort hadn't created Horcruxes in the first place, he would've never accidentally created his connection with Harry and allowed anyone outside his trusted Death Eaters a sliver of insight into his master plans.
Voldemort Took Unnecessary Risks
Once Lord Voldemort completed his Horcrux collection, he became paranoid to anyone that could become a threat and often took unnecessary risks. When he heard the prophecy that spoke of a boy who could destroy him, he became enraged and set off on a mission to destroy this baby. But if he didn't have his Horcruxes, he would've looked deeper into a few things. First, he should've known logically that any regular wizard would have a nearly impossible time destroying him, as he held seven Horcruxes that would keep him coming back to life and an arsenal of dark magic spells. Even if this wizard made it their life's goal to see to his demise, he would have always had a way of returning. This is not something a regular wizard with only one life would do, and further proves his Horcruxes took away his sense of reason and made him take unneeded risks.
Secondly, he never verified, between Neville Longbottom and Harry Potter, which one was the Chosen One. He randomly picked whichever baby seemed more likely to him and set sail to rain terror. Again, if he was logical and retained his sense of morality, he would've waited until it was confirmed or investigated deeper into the matter, saving him from Lily Potter's spell that lead to his demise that night.
The Horcruxes Made Him Arrogant and Careless
In having his Horcruxes, Voldemort believed he was untouchable and became extremely arrogant and careless as a result. He never anticipated that the Potters, or any other wizarding family who wasn't a part of his cult, could defeat or severely harm him. This is a mistake only someone who feels superior to anyone else would make. In a world full of a vast range of spells, a wizard with a sense of morality would attack more strategically. Any other time that we know of, Voldemort attacked with his fellow Death Eaters, often letting them handle the slack, who in this case, would've been Lily and James Potter.
Since he felt a sense of arrogance and had his immortality in mind, he went alone to the Potters' house and did not conceal his plan of attack, giving them a large amount of time to prepare counter-attacks. This lead to him defeating James Potter on his own, leaving Lily plenty of time to put her spell on Harry that rebounded on Voldemort. If he had approached the Potters' house that night with a few of his followers and concealed his plan of attack, it would've left no time for Lily to put that spell on Harry. This would've given Voldemort the full ability to kill Harry without any consequences. This proves that his Horcrux creations severely affected his state of mind, leading to him making huge mistakes and ultimately defeating himself. Most wizards live about 137 years, while Voldemort died at the age of 71.