I see little point in running those old systems on bare modern metal, but having a working VirtIO stack could be very interesting indeed (I’m „vibing” one for OSX systems starting with Tiger). One could use old applications or develop new ones for old systems, but have things like filesystem snapshots, networking, etc managed by a modern system.

Now I'm getting my hopes up of someone porting OSX Tiger to Apple Silicon natively . . .

Exactly! This is the only place I like using LLMs, making old stuff work again, breathing new life into it. Containing it so it doesn't create security issues.