Player's League - Legends

I am curious if the Player's League still means anything? I just reached the "Legends" level after nearly three years and I was pretty excited at first. Then I noticed that more than 1 1/2 million players have "Legend" status, and there are more Legends than there are at any other level. "Champions" has barely a million, and all other levels are less than a million. SO I guess what I am asking is, where do I go from here? Is there any further incentive to keep track of my Player's league points, or is reaching Legends the only goal?

There's currently nothing else. There are plans to change the way the leagues work but it probably won't happen for a while.

I'm ranked between 800 and 900, and practically every time I get sus about my opponent's move and check their profile, they're #1 ranked in legends league. At 800 ELO somehow.
It's got so that I check my opponent before the match and abort if he's legends league at that low ELO.
Like right now #1 in legends is 2000 ELO. #3, who I just played, is 800 ELO.
What does legend's league even mean if a 900 ELO can be #1 like I saw a week or two ago?

Leagues are a measure of how much you play, nothing else. If you play more games than others in your division, you'll tend to promote.

I don't know. I am in the legends league too but never thought about that