You missed the point where I linked the thread proving the OP suddenly found out Rogues are not top dps so he decided to fotm reroll, apparently he didn't buy full inclusive package with 2 BIS leggos in your mailbox together with the level boost.
Kinda reminds me of Fragnance who suddenly found out monks are good dps this patch so he rolled one, got boosted by his viewers, then got sephuz and ragequit. I mean from a guy who runs m+ all day and split runs in hardcore guilds I'd expect he has every class he'd ever wish to play prepped for ages. But hey, monks are supposed to be a shit class and they suddenly aren't, what a surprise.
Earlier in the expansion it was hard to collect all leggos and even harder on more than 1 char, it required nolife grinding. But at the moment it's just a factor of how far ahead you planned, and playing, even casually. I finished mainspec on 4 characters. Just because I didn't come to a revelation I want to play that class a week ago. It didn't take nolifing, but months of 1 raid clear + 1 mythic+ for chest. It adds up. There are faster ways for those with more time on their hands or willingness to "farm" on 1 character.
With 7.3.5 on the horizon, you'll be able to get 2 legendaries per week by focus farming on 1 char - one from the essences, one from normal blp farming (as many people claim that is the rate if you focus farm blp efficient content). It's still 6 weeks in that case from fresh char to full set for 1 spec, maybe a bit less since first 2 have increased drop chance. But that's still much better than taking 4+ months as it was in Nighthold, or never being able to reach it at all at the start of Legion with 4 leggo softcap.