AFAIU each Android manufacturer has their own ad-hoc battery optimizations and opts-in most apps to it by default and users need to opt out. It's a wild west.

AFAIU each Android manufacturer has their own ad-hoc battery optimizations and opts-in most apps to it by default and users need to opt out. It's a wild west. I think stuff might work for a while when screen is off but if the phone lies idle for hours, apps get killed etc. and the phone checks for notifs only once in a long while.