can’t you alleviate this by changing a couple settings?
IIRC by setting your app’s battery usage to “Allow background usage”, and its battery optimization to “unlimited” (there might be others, I’m just repeating what I’ve read and remember).
Unfortunately this isn’t enough. Battery optimization is disabled for me. There is a single settings entry regarding the number of background processes, there is no “unlimited” option and it doesn’t seem to make things better when tweaking it. Some people have another entry, but this isn’t the case on my phone.
Last but not least, the app must be A15 compatible. I do my Play Store app updates manually and read the “what changed” part: A huge lot of updates lately were just for A15 compatibility, and I guess it has something to do with this.
My apps update automatically, and I just checked they are all up to date. Yet the problem is still here. But honestly if the app devs have to change their code because of android’s update, then it’s just an absolutely terrible update.