This is my theory. Game movies are currently big. And an action film in a setting like GTA seems to be what films are about anyway, so it would fit well, wouldn’t it? I have this in my back since a while and nobody is talking about this. Now with the Netflix deal, it looks even more like it could happen.
Note: This speculation is just my gut feeling, but based on facts.
I’m sure they could. But what would it bring? GTA doesn’t really have anything unique other than it being a secondary world (essentially a parallel earth with names changed around).
Any GTA film could easily just be a run of the mill heist/gangster movie, because all GTA does is emulate pop culture.