I'm running a 4k monitor from the HDMI port on my M1 MBP with Asahi. I was thinking the same, so discovering a hdmi port was quite a nice suprise, especially since only 3xUSB-C
I was thinking of getting a MacBook Air and I think it doesn't have a HDMI port. But good to know that the HDMI port in MBP works. I will take a look at them.