Catalina didn’t kill XQuartz, nor did Big Sur. It still works fine, though it hasn’t been updated in 4 years. It also did not break OpenGL, only deprecate it.

Catalina didn’t kill XQuartz, nor did Big Sur. It still works fine, though it hasn’t been updated in 4 years. It also did not break OpenGL, only deprecate it. macOS is still stuck on a many-years-old version of OpenGL, but what worked in the past continues to work. Even Apple Silicon Macs will support it.