That's what sort of confuses me.

If you're no longer running a 680x0 and the custom chips that defined what an (original-series) Amiga was, and you can't plug in any of the historic peripherals (I don't even see a 9-pin joystick/mouse socket!) why bother with PowerPC in $current_year?

I can sort of see the story for projects like the "Denise" board where it's basically a way to create a new hardware 68k Amiga (although modern replacements for the Commodore silicon might be desirable, so we aren't just desoldering/desocketing the same 30-year-old chips again and again).

But if you've already given up the main aspects of classic Amiga hardware and chosen emulation as the road forward, cheapest commodity x86-64 or ARM products would be fast enough to emulate pretty much any mainstream 680x0 option and the custom chips. I could see a small niche for a PPC coprocessor accelerator for the small sliver of "PPC-native" software if the current emulation isn't fast enough.