My 2014 Intel MacBook Pro has Power Nap and behaves the same when it comes to radios when compared to my M1. It's not new.
> it was resulting in initial network connection slowdowns or errors with buggy online-only apps.
Just because your radio is up, connected to the AP and keeping L2 active doesn't mean your processor/OS is keeping TCP connections up, or even talked to the hardware and updated itself. It's normal.
Find My doesn't keep a connection open 24/7. It pulls the commands the moment system wakes up. I have it enabled and check my devices sometimes, and it's not extraordinary to see "15 minutes ago" or "2 hours ago" for a laptop sitting on the table, not connected to power and its lid closed.