Ah ok thanks. Is it because of the new M1/M2 architecture?
I think Asahi Linux is where the progress is. Looking promising but rough. Lots of reverse engineering.
T2 chips aren't supported too well either.
That's one aspect. They implement UEFI, but no support for user loading of certificates. So you have to disable Secure Boot, making it considerably less secure than alternatives. There's no interface or drivers for T2, so again less secure than alternatives with TPM 2.0.