The villains are usually interesting, but that can only keep you going for so long. The problem is that the main characters are either just entirely nonexistent (like in FC5 and, if I recall correctly, FC2), or they're just utterly boring and barely there (FC3 and FC4). To be fair, this is a problem that hinders the industry as a whole, as very few developers seem to be able to effectively develop compelling main characters in their games. There seems to be far too much of a sense that the player needs to develop their own character, and I think that's largely a mistake, especially in non-RPGs where character customization is limited and/or largely pointless.
Witcher 3 is a perfect example of how you craft a game with an actual protagonist that is a fully developed character, but still allow the player to develop the character over the course of the game as well. Geralt is Geralt, but exactly how Geralt acts in any given situation is up to you, the player. You can choose to be an asshole or you can choose to be a good guy, or you can fall somewhere in between, and the decisions you make throughout add up to determine what ending you get. Now, do I expect every game to be that deep with its main character? No, of course not. But I think more games need main characters like Geralt who are actually interesting and compelling rather than silent protagonists who, by and large, add nothing to games.
This idea that we need a silent protagonist as our character in games so we can become said character is incredibly misguided, and I think it often comes down more to developer laziness than any actual purpose. It can make sense in an RPG where you build your character from the ground up and spend the entire game deciding what kind of character he/she will be, but it makes much less sense in a narrative, mostly linear game. And even in RPGs, I'd like to think the Mass Effect trilogy showed us all that, even in a game where you create your own character, it adds to a game significantly when your character actually gets compelling dialogue and good voice acting. Why does Far Cry 5 need a silent protagonist? It makes no sense. Your character is a cop. Why not make him or her an actual, developed character rather than a silent nobody? I doubt it would make the game anything other than better.
Hell, your FC5 character doesn't even have a fucking name, which is insanely lazy.