Not at all, as I said, if I'm wrong about how the D4 system works, that's great for everyone and I'm the fool.
But if I'm right, that's good for me, but everyone else is the fool.
The point I'm making though is that in other ARPG games, those skill enhancements come from their passive skill trees and not through an RNG item drop. With many of the build defining items enhancing or changing how a skill functions for example Voltaxic Rift in poe a bow that changes your damage type from lightning to chaos. Transforming how you would build and scale your damage.
Or Voidforge a sword that converts your physical damage to elemental damage, transforming how you would scale your damage, yet allow you to use any melee skill that dealt physical damage.
D3 is exactly this way. Your skills need the legendarys while levelling otherwise it's gonna be a long drawn out slog. New char in D3 is to get Kanais cube, upgrade rare and hope for that build enabling legendary. Then gamble shards at Kadala for another build enabling legendary.