I use Steam regularly, I don’t game on a Mac regularly. To be fair I don’t think most people use Macs for gaming. It’s been that way for as long as I can remember. Apple has a tight grip on mobile gaming though, that’s a money maker for them.
I don't play many mobile games but I tested The Battle of Polytopia when it was in beta and I still play it today. So it's not a complete loss. Android has solid emulation scene though.