Android Pie has a feature to restrict battery usage of apps. I added them all. 80 installed apps and 120 system apps. Now it runs like an iPhone. Alarms don't fire, so Clock is the only app I didn't restricted.
I have an expensive flagship-level phone (Razer, 1st gen) that in less than one year, stopped being updated. Pie would be nice. Until then, I'll just wait for the Librem 5 - a phone that will get constant updates as I'll be able to install just about any Linux distro I want on it (but I'll probably stick with the stock PureOS). Maybe I'll just go to no phone at all, my sanity would probably thank me for that.13w reply