Everyone has such different tastes, there will never be a 'greatest film of all time' that is excepted by everyone.

• Erm, have you ever watched the Lord of the Rings, or any Marvel film, or How to Train your Dragon??
• Every person has such different tastes. Some of my friends hate the films that I love, and vice-versa. I have never come across a film that everyone who has seen it has loved.
• So, my point is that there will never be ‘a greatest film of all time’, this is due to the fact everyone has such different tastes.
  (But if there was, it wouldn’t be citizen Kane!)

The argument that Citizen Kane is the greatest film of all time is based on the idea that it was revolutionary---the "pinnacle of the American studio system" as well as a critically different take on it altogether.

• Orson Welles's 1941 film has classically been held by many to be the greatest film of all time. It's come to be seen as a milestone in cinematic technique, a "landmark achievement in film" that is "entertaining, poignant, and inventive in its storytelling."

• Some claim that virtually every film maker has been influenced by Citizen Kane.

• Writing for Screen Rant, Cathal Gunning says that a certain part of the film "[I]s one of the many moments where Welles’ ambitious filmmaking allowed future directors to collapse long, complex stories into a string of easily understood images, a technique that has become so commonplace it barely merits notice in the twenty-first century. Without Kane’s two-minute marriage, viewers may never have seen Up’s heartbreaking opening scene or the unforgettable montage sequences of 2001: A Space Odyssey."

• Gunning also says that "much of what makes it hard to argue against Citizen Kane’s impressive claim [to supremacy] is the fact that any later movie contending for the title of 'greatest movie ever made' will inevitably have borrowed liberally from techniques established by Welles’ film." The movie-making innovations Welles created were derived from his lack of experience as a filmmaker; his fresh approach worked to establish groundbreaking techniques precisely because he had no idea what rules he was even breaking.

• A final argument in favor of Citizen Kane's supposed superiority, as Gunning tells it: "[A]lmost all of the movies that could contend for the title of the greatest movie ever made are built upon the techniques and innovations featured in Welles’ landmark release, whether they borrow deep-focus photography, Eisenstein-inspired montage editing, or disordered storytelling from Citizen Kane."

• Many people would not be swayed by these arguments, and of course, ultimately, there is no such thing as a true "best movie ever", since all tastes are different. (It's also in no way foolproof to proclaim, for instance, that because Citizen Kane introduced the techniques used in other potential "best films" that means it's the greatest overall. Just because it came first, the argument might go, doesn't mean something else wouldn't have arisen at some point to bring about the same thing. A question about the fundamental nature of the conditions for a "greatest ever" arises. Not to mention, there are many more cultures than just the one that created it, and what counts as "great film techniques" to one culture varies from one to the next and will forever across time.) But these are just a few reasons people have classically called Citizen Kane the greatest movie of all time.

It's true that, in film criticism and the arts more broadly, there are degrees of wrongness for how good something is in quality. But there is no such thing as one right answer.

In my opinion, Greta Gerwig's Little Women is the greatest film of all time. It is artistic, heart-wrenching, beautifully constructed and such an elegant retelling of Louisa May Alcott's beloved story. I'm incredibly biased, however - I love period dramas. If you don't then it is discounted almost immediately. The problem, then, with both my opinion and the one above, is writ large.

• Citizen Kane, in a number of ways, revolutionised film as we know it. However, with all the myriad cultures the world has to offer we cannot overstate the impact of one film on global cinema
• Logistically, no one can ever truly know the answer to this, as no one could watch every single film
• Wildly different films are brilliant for wildly different reasons, be they technical or stylistic - there is no way of accumulating a total score, and if there was that would take away from the essence of film criticism