It’s not. It’s 100% a MacOS limitation, because you can use MST on Windows to drive multiple displays on Mac hardware, the same is likely possible with Asahi Linux if they want to support it. Apple doesn’t want to use MST because they want you to buy into their Thunderbolt displays for extra monitors, or you can just use DisplayLink if you’re desperate like me.
As soon as they can make multiple displays work over a single USB-C I may be able to ditch the double dongle nightmare I have right now
I think that that is a hardware limitation, not a software one
It’s not. It’s 100% a MacOS limitation, because you can use MST on Windows to drive multiple displays on Mac hardware, the same is likely possible with Asahi Linux if they want to support it. Apple doesn’t want to use MST because they want you to buy into their Thunderbolt displays for extra monitors, or you can just use DisplayLink if you’re desperate like me.
It is hardware limitation. Those M-series chips have just a few display controllers. Even with Thunderbolt you can’t exceed that limit.