Not true. Some sell games from their own sites too. Like Vintage Story and Factorio.

What if you come back and they have a macbook?

Factorio ClusterIO megabase with only an iGPU and a pile of rack servers for running all your instances - “Objectively low end”

Its basically a CPU benchmark disguised as a game.

Depends on application and hardware. On pretty low specs you can see larger differences between operating systems.