first of all:
if you are running chrome as your browser, then likely this message will pop up, due to chrome dropping the availability to use the player. (can be fixed if you use the old versions though)
second of all:
"the webgl version is flawed, i have over 200 ping on my closest region, my frame rate is piss, and my movement is gittery. So what do i do?"
everything is simple.
get the mozilla firefox extended support release.
what it basically is, is that it functions as the latest firefox, but it allows you to use the web players option instead of the webgl's version.
https://www.mozilla.org/en-US/firefox/organizations/all/
pick your language, download the installer based on your system, run it, after the setup has been finished, run the browser, and try to play the game.
it should work, when you step in the game and you have a decent frame rate and ping.
if it doesnt work, then try a new browser or something.