The last time there was this big of a jump in performance in the mini was with the Core Solo/Duo models that came after the G4 ones.
To match the single threaded performance of the M4, you’d need a 13th or 14th gen i7 on the Intel side or a 9600X. You might even be able to build a full system at the same price point, probably for the first time ever.
It’s incredibly enticing: the price, form factor, performance, connectivity.