Minecraft used to run at high FPS, after some updates it was running at a very low framerates

That doesn’t seem to be the case… The F3 Debug screen reports it using nvidia.
removing the prime-run from the wrapper commands makes the game report using the intel iGPU.

aight, I’ll try removing optimus-manager and see the performance.

EDIT: yes, removing optimus-manager restored the performance. Thanks!