The other guy mentioned:

they already said they were Mac only because they used Metal for rendering

And you say:

Metal is basically the only graphics API on Mac

So they're on Mac bc they need Metal, but they picked Metal bc they're on a Mac? It's circular and friggin weird man

Not to mention there are cross-platform wrappers that will pick from all three depending on system - some that are very prolific among Rust devs (Zed is coded in Rust) like wgpu, for instance. They could've used wgpu and supported all 3 from the get-go and it would be easier than doing Metal anyway!

And so picking just Mac and/or Metal first is suspicious.