I wondered the same about Linux installers. I'm installing some kind of debian minimal which will take 300 MB on disk. It should be installed in a fraction of the second. Instead it takes minutes. All installer should do is: dd pre-assembled Ext3 filesystem from ISO to disk; extend filesystem to the desired size; write some configs like fstab. It could be really fast.

My guess is that nobody really took the time to optimize it. Installation is only one-time procedure and even it if takes a hour, who cares.

What you describe is the cloud image. You can dd it to your hard drive and it should work as is (initial password will be displayed on first boot).

As for Debian, the slowness comes mostly for fsync calls I think. You should be able to use eatmydata to avoid this. See: https://people.skolelinux.org/pere/blog/Quicker_Debian_insta...

Yeah, I know, my point is that ordinary installer should do the same with ordinary installer UI rather than trying to install every deb package over and over again, running its pre/post scripts, etc. What's the point? It should be deterministic anyway.

thatd work if it wasnt for (some) settings of course. but even then, image and then update /etc and friends and done but here we are

I jumped on the upgrade bandwagon quickly this morning and the entire upgrade took about 15 minutes on my M1 MBP 13".

Presumably, you're experiencing the same download issues my work MBP is experiencing. It's been downloading for over an hour and is just barely past 50%. My Internet bandwidth is 10G real-world and un-busy, so presumably Apple's CDN is getting hit good.

At much of it, the OS and even applications actually seem to be running. I remember a macOS update with the full-screen progress bar, where a few minutes in, a browser tab suddenly started playing music, with no way to turn it off...

Other 58 minutes is collecting telemetry

EFI updates are sometimes included with new versions of macOS.