Find your biggest weakness and work on it. Defense and minor piece endings are among the least studied things so maybe those? It's individual.
Over 2300

Notice that 2300 to 2600 is only 300 points. Same as 1300 to 1600 right?
Not really :p People get stuck at higher levels because it gets really hard as you continue to improve. There's nothing special about 2300.

It's not when you load the page, it's when you click "post comment"
I clicked "post comment" before you.

Notice that 2300 to 2600 is only 300 points. Same as 1300 to 1600 right?
Not really :p People get stuck at higher levels because it gets really hard as you continue to improve. There's nothing special about 2300.
This is the simple law of diminishing returns. It's much easier for an overweight guy to slash 5 seconds off his sprint by losing some weight and simply cutting sugar out of his diet than it is for an Olympic athlete to shave .1 seconds off his sprint (and simply cutting out sugar doesn't cut it for those guys, they need nutrition plans laid out by guys with degrees in that sort if thing to stay competitive) The effort for the later is also much more since it requires ever stricter diets and workout programs. Chess and any skillset in general operates off the same principle.
Why do quite many AC players get stuck at 2260+ in slow chess?
What does it take to move over this barrier?