In my opinion, the best 10% doesn't matter. At the time I thought that 1000 elo played very well, then when I reached 1000 elo I thought that 1500 elo played well, but now I'm 1500 and I think that 2000 elo played well. It's right because if you're happy with what you have, you just don't want to develop any further. But what I always knew is that I play badly and even if I'm in the top 4% I still know that I'm stupid.
Went from 1000 - 1394 (so close lol, now 1370) in 2 months from simply working on tactics mentally and thus learning to calculate mentally during games. Also played fewer blitz games and spent that time/energy solving instead, and keeping my 15/10 games to once per day w/ no distractions. Fwiw!