I think Rockstar Games is one of the few studios whose track record proves that they really can take their time developing such games. Projects of this magnitude need to be approached gradually, and most of the industry collapses when huge amounts of money are invested in a studio just because someone once worked on a successful game. You need a team with accumulated experience and a habit of releasing complex projects together. This is an extremely expensive risk that in most cases turns out to be unsuccessful. Only when a studio has proven its worth many times can it afford what Rockstar does. But it takes a very long time to reach this level.
Purkeypile noted that only a few companies are able to withstand such long development cycles, and GTA VI has become an illustrative example of large-scale modern blockbusters. He also suggested that a possible GTA VII might be dedicated to Texas and incorporate elements of immersive sim.