Earlier quoted context omitted.
You can disable "Battery Optimization" per app, so this isn't very restrictive. It just applies by default.
I'd like to do that, but when I 'exit' an app and/or swipe it off of the list of program cards I want it to ACTUALLY exit (at least within 30 seconds).
Okay so maybe you could argue that if you never "swipe kill" the app it should be allowed to have background services executing much like e.g. Slack on macOS. But you can't even do that. Having your ui in the recent tasks list does not exempt you from background restriction.