During Legion, did you need to grind artifact power to paragon levels before Trial of Valor, farm M+ until you get your best in slot legendary or switch weapon and start AP/legendary grind from 0 when Blizzard buff other spec?
For sure you didn't need it complete content, because at this level main thing to do is coordination and mechanic execution, above average numbers just makes up for your mistakes. It's cutting edge level (on release) where players needs both perfect execution and maximum possible numbers.
Of course I'm talking about situation when balance will be usual for Blizzard standards (so still far, far away to be optimal for many people), not situation when some Covenant will be so OP that all sites will have to put ALL MAGES COME TO VENTHYR OR YOU WILL BE F*CKED message or something.