I played wb for quite long now 1.5 wb is not requesting any skillfull play since u don't even have to time stuns cuz its now knock down but demon barb has a lot better solo/mass/small pk play, barb is chi machine in mass pk, almost unkillable in 1v1 and small pks meanwhile u do good dmg, sage wb is pointless since u can't do much except maybe tank a bit more than demon and tanking only matters in tw, so I'd say go demon
Tbh tanking is not just an advantage in tw for barbs. Sage barbs good in squad pk or mass pk as well. Ofc not that good in 1v1 but its not true that sage barbs only useful in tw. Just wanted to add that.