We will only know once AMD APUs on TSMC 5nm will come out. If you look at 7nm options, A12Z and AMD Ryzen 7 4800U, the former has better single thread, but the later has much higher multicore.

Unfortunately, I could not find any data on TDP of A12Z under full load, so it is impossible to guesstimate at the moment which design is superior.

UPD. Actually, there's this: https://www.anandtech.com/show/16252/mac-mini-apple-m1-teste...

If I am to believe the successor to 4800U will gain 10% perf from switching 7nm -> 5nm, design-wise it matches M1.