Graphics layers are fairly stable, OpenGL still works, and Metal was introduced 10 years ago. The issue is that they switched the CPU architecture three times, from PPC to Intel to ARM, and dropped 32-bit support to make the ARM transition easier.

The question are: would Valve had still made a profit if it sell only 50000 copies pre-orders and then the normal copies? Probably yes. Would it be easier to Valve to make their games work on the current macOS? Probably yes, they had the updated CS2 already working on macOS, but then canned it at the last minute for the usual "no one will play it on Mac".

But Valve didn't even try, they ported Steam to macOS in 2010, ported a bunch of games to 32-bit, when every Mac out there was already 64-bit, and called it a day. They didn't even fix their store to properly show which game is 64-bit or not, or fixed their Steam Input to properly support controllers. They left the app half-broken and then complained they had not enough users. Steam is still a x86_64 app after 4 years of Apple Silicon.

On the other hand Apple didn't even care about games too much. So yes, no one really cares.