Sorry but the notion of clearing an enemies head from a standing jump while wearing armour belongs in Super Mario or even throwing or shoving an enemy dozens of feet likewise breaks any kind of immersion in what is a fantasy adventure with adult themes. Whilst the game inhabits a fantasy world with magic and monsters you still need some basis in realism or it just feels goofy, which is precisely what it is, so in that sense the combat does clash with the narrative in my opinion. I know plenty of people who are stronger than me but I can run faster and probably jump further than most of them.
So yes while I agree "I am not looking for this kind of fantasy", I think BG3 fundamentally fails on presenting a coherent narrative and game world.
Also, during early levels we are not really 'larger than life heroes', I would assume that would come later in the game when we much higher levels?
Right, and ripping off a giant superhuman monster's arm by wedging it in a door and strangling a dragon with your bare hands are equally impossible feats, yet there they are in Beowulf. Heroic Fantasy is a completely legitimate genre of fantasy. Just because you want a more grounded fantasy experience doesn't mean that is the only way fantasy can be immersive.
Also according to 5e's PHB the vast majority of people in the world will never achieve the first level of a class. A 1st level fighter isn't just a normal dude swinging a sword, it is someone so incredible in combat that they have mastered every weapon type and can push themselves beyond normal limits to perform feats like Action Surge and Second Wind.
If you have a level in a class you're already exceptional.