(can't edit my post but for Planetside 2 the launch option is actually --disable-gpu not --disable_gpu, oops)
ok so here's what happened, sry if it's lots to unpack
I think the crashes were coming from the same issue described here, I had a "version of Steam" that was initially started with LSI on. I removed Steam and LSI, deleted my entire /.local/share/Steam folder and the home /.steam folder, reinstalled Steam, made sure LSI was disabled, then started it up.
Planetside 2 now runs fine, those crashes aren't happening. It could probably also be attributed to me not alt-tabbing this time and being more "careful", but I was able to play for a solid 10 mins or so before quitting so I'm 90% sure it was LSI.
So I joined a game (on Indar I think it was) and yeah I see what you mean, it doesn't perform very well, but it's tolerable IMO. I think it was also this way when I recorded the video. I don't usually check my framerate because once I do I can't unsee it and I don't focus on the game so I guess I didn't notice.
When I started I set it to medium settings, and again got 150+ fps in the hub but the moment I warped to a zone it dipped down to a range of 40 - 60. Even on the lowest settings. Weirdly, it performs the exact same maxing it out.
Screenshots here with Steam's frame counter up left. They both perform the same, the scene in the screenshot is just a little different hence the different rates.
Lowest settings:
Max settings:
Weird how changing the setting has no affect on performance, Halo Infinite is the same. So it isn't just you, I guess that update did some things but at least it's still playable, I wonder how it performs on Windows with the decade update?