What build should I use as barb to do endgame? At lvl 125 it sux even with a 420-575 sacred labrys
Thing with whirlpool is, that damage is correct vs stationary target that doesn't move away/teleport. So it wont be the most efficient skill in every case.
As for damage for endgame, screaming eagle setup, paired with banish proc, -enemy all resistances on gear is vastly superior in terms of damage numbers. You can count on 7-8x more damage with it.
Ofc it has its flaws, need to debuff every screen with screaming eagle, which makes it pretty annoying for farming. But for straight single target damage, conventional phys based build is no match.
This build was discussed in this thread more than once, feel free to check some pages back.