Thanks. I'll read more about it, starting at https://wiki.archlinux.org/title/Zswap and https://en.wikipedia.org/wiki/Zswap (interestingly the Archwiki result was the top result). From Wikipedia:
Instead of moving memory pages to a swap device when they are to be swapped out, zswap compresses them and then stores them in a memory pool dynamically allocated in the system RAM. This way, writeback to the actual swap device is deferred or even completely avoided, resulting in a significantly reduced I/O load for systems that require swapping; the tradeoff is the need for additional CPU cycles to perform the compression.
To me, this sounds like its the opposite of full RAM. It tries to avoid writing to swap file, if I understand it correctly. Or bundle them up to write a huge chunk only once, like filesystem do on hard drives or SSDs in example, to reduce writing each single block. Do I understand it correctly? So one would need a huge amount of system RAM to have this work effectively. I have 32gb RAM and practically never fill it up when playing a game, usually. So maybe its worth exploring this option. Overall seems like most people with their current setup aren't affected by this Linux update.