I use https://f-droid.org/packages/mattecarra.accapp/ (with a rooted phone) to keep my charge levels within 5%-85% of the manufacturer battery range.
Most manufacturers made a decision to set the range their devices will charge to based on what is less likely to fail so quickly you’ll get mad at the manufacturer, but they trade off significant battery life for slightly higher design capacity (or perhaps more likely, they see shorter battery life as a feature not a bug, as long as it doesn’t catch fire, since it will mean your phone becomes e-waste faster and you give them more money).
Battery chemistry tells us that avoiding those extremes of high and low charge (shutdown earlier on low charge in the rare event that happens, stop charging at a lower level) drastically increases battery life - it is aligned with my interests, even if not the manufacturers’.
This seems extreme for the long tail of hobbyist apps. Finding 20 testers seems like a huge commitment for an unproven app, and I’m sure it would be a hurdle many apps currently in Google Play would not have gotten across if it existed then.
I wonder if this is a deliberate attempt to shut out hobby apps from their app store for whatever reason, rather than a good faith attempt to improve app quality.
In parallel they are also forcing people to publicly attach their real name to apps (people have long had to tell Google who they are to get in the app store, but not to make it public) - which might be another thing that is no big deal for big companies, but many smaller hobbyist app devs might think twice about doxxing themselves given how hostile people are on the Internet these days and how many crazies there are out there.
I used to buy Xiaomi products because of the bootloader unlocking, but in practice it is a dystopian nightmare - they have built it so to unlock the bootloader you need a cryptographic signature from them, and they don’t give that out all that easily.
You have to sign up for an account with them, use a Windows-only tool to request unlocking, and they have a long wait period (deliberately imposed) to unlock, which sometimes randomly restarts. The wait period is different for different models, and can be weeks.
Their support are unwilling to help unlock immediately even for replacement devices where you want to get up and going quickly - if your device breaks (they are not the most durable phones IMO, as you note) and you get a replacement, you’ll have to wait the time again before you can restore a backup of a phone using a custom ROM.
It’s possible they have improved, but because of their attitude around what I can do with my own hardware, I’ve stopped buying Xiaomi gear.