You might as well question the realism of the rules of chess.
The rules of a game dont have to make sense and dont have to be realistic.
They only have to work as a game.
D&D5 is optimized to be easy to handle with nothing but pieces of paper, a pen, and a couple dices.
Thus things are kept simple. Not realistic.
show me how you dodge sword in plate armor :F or hit from crossbow xD
The weight of plate armor is distributed across the body in such a way that it does not significantly hamper mobility, so in real life you would dodge a sword while wearing plate armor pretty much exactly as you would without it.
But that’s besides the point, as the post you are responding to pointed out already.
This isn’t going to change. Your objections are irrelevant here.
