Just to clarify, are you stating this as a truism that I may be oblivious to, or as in your own personal experience?

Otherwise, this is proof that two different people can have such vastly different experiences. I find modern AAA games to be rich of actions and choices. There are more "open world" games now than ever. And while your statement is true of the main storyline, I think there's so much diversity in games now that the main story line is often just a "thing you get around to" after you get bored of whatever side quests or exploration you are performing.