Parmandur
Book-Friend, he/him
As a generalization? No - that generalization would be a vast overstatement. That'd be like saying my soda having an ice cube in it makes it overall a "frozen drink."
Do some people come up with table practice ("house rules" effectively) in which they make major use of those gaps? Sure. Does the game, as written, give much support or advice for doing so? No.
So, is the game freeform overall? No.
And that, in essence, is the point - the game does not give adequate support for this kind of play to say that the game, overall, is this way. Individual tables may produce such support, but that should be attributed to the table, not the game.
The game system is responsible for producing a system in which to play a game (tau-tau-taoolllooooogy).
5E has a system for free-form action resolution, that can be scaled to fit as desired at a moments notice, and provides the math to do so in a straightforward manner in a fashion that is free from constraint (free-form, one might reasonably say).
At any rate, it is certainly more free-form than 4E (which uses the same system but with more fiddley bits and limitations, being therefore less free in form).