The Phantom Pain is a little weird when it comes to player freedom.
You have tons of options for how you can approach a mission, but it asserts a 'correct' way of playing. It does this with the Mission Score system, and the Fulton system.
My options, when attempting to do a mission well, are filtered through "I should do this without being seen" and "I should do this trying not to kill anyone", which restricts what you are able to do by quite a significant amount. Then there are things like Air Support automatically removing the possibility of getting an S rank, and therefore being things you mentally check off of your list of options.
You have dozens of weapons, but when you filter it through the two major factors I mentioned above, you really only have a few. Your tranquillizer dart pistol, perhaps a silenced rifle you can develop (and its tranquilizing variant), a variety of grenade and decoys. Assuming you want to play the game well, which I assume most players go into a mission intending to do, you don't have all that many options.
Compared to something like Far Cry 2/3/4, where there isn't really any defined 'correct' way of doing any mission or outpost, I find that's where options erupt. "I'm going to tear through this place with a grenade launcher" sort of stuff. You can do that in The Phantom Pain, but will most players? I don't know.
You have a lot more freedom in infiltration, though.