Sounds like your M2 is hitting the TDP max and the Ryzen box isn't.

Keep in mind there are Nvidia-designed chips (eg. Switch 2) that use all of ten watts when playing Cyberpunk 2077. Manufactured on Samsung's 8nm node, no less. It's a bit of a pre-beaten horse, but people aren't joking when they say Apple's GPU and CPU designs leave a lot of efficiency on the table.