Mac system requirements appear somewhat unusual. Are ARM Macs unsupported?

Something like this exists :) blog.mapbox.com/realistic-te...

It is, at least partially. However, GLTF lacks certain features and was designed to be most compatible with web graphics (it reuses constants from WebGL). But I know that they are working on adding stuff to make it closer to being a good option, e.g. physics.

Yeah, the industry needs a suitable asset interchange format. FBX is, as far as I know, widely adopted, but it has only a closed-source SDK and no specification or description. USD looks promising, though, as it gains traction in the industry.

I'm curious about differences. Unity basically converts blend files to FBX under the hood.