[frupert52]

I have been seeing all of the above problems on my 16GB M1 MacBook Air for probably at least 6 months now.

WindowServer has consistently been the main culprit but occasionally other apps like to chip in where they can too. Often that means there isn’t one single process which I can kill to reclaim enough memory to continue working without being promoted again or having MacOS forcibly close all my applications on me. As a result, reboots appear to be the only real solution for me.

Interestingly though, in the past few weeks I have been working with similar numbers of open Sublime Text windows as yourself and I can confirm that since then, ST4 has been a regular and serious offender when it comes to memory usage in Activity Monitor.