You can already get that by replacing the cpu with a pistorm:
https://linuxjedi.co.uk/2021/12/27/800mips-amiga-with-emu68-...
https://linuxjedi.co.uk/2021/12/27/800mips-amiga-with-emu68-...
That aside, I don't really get this nostalgy for these systems. I don't care about Doom, or some port of Quake. While 68K assembly was much nicer for me than anything common today, what do I get from that without a usable Browser, Office, "daily driver" apps? Show me how to port Firefox, Chromium or something functionally equivalent to these, and how those perform! :-)
Or Blender.
(Or Android 68K! (Giggle))
Apart from the nostalgy factor, I suspect there would be no actual benefit from such a system. I doubt m68k would compare well to ARM or x64 in terms of compatibility or modern-app performance.