I don't have much sympathy for this idea. The vast majority of apps don't need to do anything in the background, but almost every app thinks it's the only app on your phone and wants to be running and online 24/7 so it can constantly send you notifications, mine your personal info, and upsell you on crap you don't need.

This is why we can't have nice things. It's a tragedy of the commons where the commons is your battery and your data and your attention.

Phone manufacturers try to restrict this nonsense as they should, but the better solution is to give users complete control over background behavior, with the default being "none."