So in other words, heavy armor svcks compared to light armor, and the only good thing with heavy armor is the looks?
Without the use of one of the stone effects..
If you abuse the synergy with the crafting skills it comes down to stamina regen or stagger reduction. You will hit the cap in anything but the very basic armour.
If you don't abuse the crafting synergy the armour matters as light armour will never reach the cap (close with smithing perks but not quite - and without smithing perks not even close).
It also affects the spending of perks, without smithing perks I'm not sure if, or how close, you come to the cap even with Heavy armour.
So it's largely down to your playstyle, and the choices in perk distribution.
So no not useless.