The M1 is great because it's fanless. AMD Ryzen is superb on workstations, but let's see if they can deliver a nice fanless or low power option. I hope they do.
The Ryzen mobile chips, including the upcoming Ryzen 7 5800U mentioned above, have a low 10W (configurable up to 25W) TDP. That's in the ballpark of Apple's chip.
On laptops, more power efficiency maps directly to increased performance (turbo clocks provide higher performance in bursts or at the expense of your laptop's fans sounding like a jet turbine).
It’s almost like power efficiency is all about the process node. M1 is 5nm. It’s a great core but it’s power profile would not be so impressive at a larger node.