There’s always going to be holdouts, but as a company you can’t really shape your OS development path around them in the long term. Eventually, they’re going to have to go unsupported.
For 68k/PPC Macs specifically, emulation could really stand to be better, though. Compatibility for DOS and old Windows releases is extremely well covered by FOSS projects, but the same has yet to occur for old Mac stuff.
Dual boot is nice but can be a bit of a pain on its own, though. Rebooting is very disruptive if you want to quickly switch between work/play for example.
Linux VMs work OK-ish but UIs in them to be pretty laggy compared to running directly.