Probably not as good as walking/running...but the elliptical at a gym could really do the trick with very little knee pressure.
I ran a lot when I was younger; had to stop because of a knee injury, too. It never stops sucking but hopefully you can find something better on your knees that still helps you.
The fact that running reduced your symptoms is absolutely awesome, it's never been as effective for me. It's proof that you CAN beat this, that things can change. That is the ULTIMATE win. You've got this!
I think the only thing stopping me from gaming 100% on bazzite is Helldivers 2 anti-cheat (so fucking tired of these rootkits) isn't Linux compatible last time I checked.I hope that shit changes soon, because I can't wait to fully remove windows off my extra hard drive.