I've since sold my Quest 2, but when I had it I was able to play my entire SteamVR library via ALVR at *comparable performance to Windows. Elite Dangerous, modded Boneworks, the whole nine yards.

*Definitely not 1-1 with Windows, but easily at 85%+ of the performance. It does require some tweaking of your settings, and definitely benefits from a snappy network setup (wireless was basically not an option for me due to my housing/wifi situation, but the link cable worked great and was even easier to set up).