I completely agree with the Power Armor in Fallout 4 looking silly like a gorilla, but as for the bulkiness I actually love it. I think it's the movement animations that ruin the look of it for FO4/76. I combined two mods for FNV for Power Armor that I think makes it look much better animation-wise than the newer games, here's some GIFs I made just now from my modded playthrough for demonstration (and for demonstration purposes I toggled God Mode/Easy Mode on):
Personally I think the Power Armor looks miles better when not stanced up like an oaf or gorilla. I get they were going for the "Human Tank" look, but Fallout 1 and 2 showed perfectly you can have bulky Power Armor and walk more imposing and dominant than like Quasimodo.