Recently the trailer for the film "Joker" was released, one of the few films focusing on the comic book villain rather than the hero. This made me wonder whether a film that forces us to follow a villain can work or not. To start, let's look at some preexisting films that already follow the villain.
Sadly, there are not many that I can think of off the top of my head. The only two that come to mind are "Venom" and "Catwoman." Neither film could be called a classic, and both films focus on characters who have some level of redeeming the moral value to the point that you could easily label them as anti-heroes instead. There is rarely a film that starts a character who is flat out unlikable.
Even the most despicable villains have some quality that humanizes them on some level. The Joker is a violent psychopathic serial killer who takes glee in his work, but his twisted sense of humor and tragic backstory makes him a fascinating character. Loki is a violent trickster who's willing to murder and steal his way to power, but he has a weaselly sense of charisma and smugness that makes him entertaining to watch.
Without that humanization, the villain would just come across as a generic bad guy with no real motivation or personality for the audience to latch on to. This does not mean that a villain should always be sympathetic, but you have to give the audience a reason to care about a story from a "bad guy's" perspective. What makes this character, their actions, their personality, and/or their motives so compelling to an audience?
Joker is a good example. The Joker is a violent butcher who does what he does out of a sense of gleeful nihilism. The Joker is more of an idea than a character. He is the embodiment of a chaotic and random world where anything can go bad at any time for any reason. He does what he does because he finds the random and uncontrollable acts of chaos and violence in the world amusing rather than horrifying.
Loki is charismatic wannabe charmer who has delusions of grandeur. While extremely intelligent, Loki lacks the gifts of strength and agility that make the other gods, especially his brother Thor, and believes his lack of these tributes prevented him from becoming the next king of Asgard. He has no interest in actually ruling but wants the respect, admiration, and power that comes with the title. He behaves like a spoiled brat and a drama queen but has the intelligence and sarcasm to make that entertaining rather than annoying.
These are just a few examples I threw out there, but I'm sure there are others you could get a good movie out of. While we tend to relate more to heroes because they are typically morally sound and likable, villains can be very interesting characters to explore in stories of their own. Hopefully, we'll get to see some of those stories very soon.