Edit: and XQuartz (X11) with OpenGL comes in handy once in a while too...
Also, it seems to me that the better option in the long run for legacy game support is to just run a VM for the highest degree of compatibility.
EDIT: As a follower of https://mesamatrix.net/ I don't think it would be unreasonable to say about 3 years to get something that kind of works, five for something semi reasonable, and 8 for something at modern open gl level.
Edit: and XQuartz (X11) with OpenGL comes in handy once in a while too...