tldr; nicely done, but extravagant for sure. 
I'm going to disagree with this take. There's a subset of players like yourself that do not value cinematics much (they are perhaps a bit overrepresented on this forum too). That's perfectly fine, different strokes for different folks. But I will argue that the cinematics in this game are essential to its success, and not an extravagancy.
Video games are an interactive medium, true. They are also a visual medium. Seeing something happen matters. There's a narrative depth to cutscenes that you cannot emulate with writing or speech. And I'm not only talking about the big story moments. It's the little things that matter the most: a character crouching to pick up an item, a quick hand gesture, the facial animations. It all serves to immerse you into the world. A significant part of the fanbase is getting hyped at the moment about the possibility of a hugging animation being developed. And I don't blame them. Near the end of the game there's a moment when you can choose to spare or execute an enemy. If you choose to kill, your character will take a dagger, crouch, and plunge it into her vitals. That cutscene adds gravitas, which would be absent if you just walked up and killed her with a default attack.
It boggles the mind what this game could have achieved if it DIDN't have to keep cinematics in mind.
This is the crux of the issue, isn't it? You say it takes a lot of resources to do this. I'm not a game dev, but that seems reasonable to me. Maybe the game would be twice its current size if they minimized cinematics or went for a more linear structure. Or perhaps there would be even more player freedom. But would that improve the game? If you push the player agency argument to its limit, you end up with something like dwarf fortress. A game with a passionate community to be sure, but not something I would ever play myself.
It's all a balancing act in the end. Larian went for a quality over quantity approach, and it paid off.
