It's very debatable.
I really don't think there is a right or wrong way to do this. there is just different way that will please different people.
As for realism and immersion, first of : we're in a fantasy world with magic, differents races, planes of existences, dragons, magical beast and so on. You also have to take into account that an adventurer is not just a normal human being.
If you want to feel like your character is a normal joe, well, he should have 10 in all his stats, which is the commoner stats block.
When a character with 18 strenght is breaking a door, it should NOT look normal, IMO. It should look impressive and inhuman because that's what 18 str is.
It would be hard to make a game where every animation goes with the stats, races and class of a character.
Personaly, I was so happy to notice fall damage from one of those "epic" jump in the underdark. They already made so much in so little time, I'm just very impressed.
In a perfect world where they would have infinite time to make everything, I would agree that it would be cool if you could see a wizard using his material component when casting spells and everything like that. But, I mean, you realise how much work that is ?
It would already be amazing if all the spells in the books makes it into the games. We can't ask for too much.