Background process doing some sort of migration or other data conversion between versions? Strange the device wouldn't wait until during the night while plugged in, but without context, that might not be an option.
Kind of sad that we don't have a top or process viewer. Or free -m / open system. This makes me yearn for an open source OS on my phone again, I may have to look into a pine phone.
If you connect your iPhone to your Mac you can run Instruments on it to figure out what is going on. I used to recently to figure out that Slack had been making my entire phone slow because it was busy looping in the background.
I agree, but it shouldn't be a classic process viewer. It should be a task viewer which has some context or understandable description. Like "photo analysis job" or "iOS 14.5.1 data migration job".
Yes... I remember back in the day I had terminal with root access on a jailbroken iPhone. You could install almost any package on your phone via terminal.
Stick a fan in it so I can hear if a background process is being run!
Might explain why my battery dropped that much, too.