Hit Locations are more heavilly used in GURPS than in Hero System in my 28 years playing and Game Mastering these games.
Thus leading to a high lethality. GURPS is also easier to break than Hero System
This was exactly my point. I didn't really "get" how Hero was generally considered less lethal than GURPS. When I started playing Hero, GURPS didn't exist yet. The HERO System was the house system that Hero Games used for its RPGs, not its universal system, and its implementation was different in the different games. Danger International, as run and played out of its 1985 original edition, was plenty lethal and gritty. It also assumed that most attacks would be Killing Attacks, in much the same way as Champions assumed that most attacks would be Normal Damage.
To me, there's a difference between "heroic" and "superheroic" play using the HERO System. Heroic means all the "optional" rules for lethality are switched on. Hit Locations, Impairing and Disabling, Knockdown, because those were the defaults in the pre-4th edition standalone games. They were "optional" in those games, in the same way that Knockback was "optional" in Champions, in the same way that rolling 3d6 for combat and Skill Rolls was "optional".
It's not that I, nor my group at the time, couldn't conceive of mixing and matching. We did that, often. We called it "Killer Champions" when we used Hit Locations, and Impairing and Disabling wounds in Champions; we also let characters have normal weapons and armor for free. It was pretty bloody and worked great for Watchmen or Wild Cards style games where more blood was expected.
I'll agree that GURPS doesn't work as well for higher power levels because of its linearity, though the GURPS Supers books for GURPS 3e included optional rules for making it less lethal and more superheroic. GURPS Supers also included the optional rule (quadratic ST) that became standard as of GURPS 4e for Strength and lifting. Which helps some, I guess, though I quit playing GURPS when 4e came out.
I would say that the vast majority of the heroic level games I've played in, from the first time until the most recent, have all used Hit Locations and Impairing and Disabling, and the vast majority of the Champions games I've played in have not.