It's great to know that this is a thing! I had hopefully assumed the real-time clock was on a supercap or something.
It's almost forgiveable with RTCs, since they're generally not required for the main device functionality and RTC reference circuits invariably use coin cells. I've got an auto-darkening welding helmet, with its main power being supplied with the same planned obsolescence nonsense, despite having a solar panel on the front! It suddenly just stopped working, and my usual course of take-apart-the-broken-thing was thwarted due to its case being ultrasonically welded together. Only when I stumbled upon a random Youtube video of someone replacing the batteries in theirs did I get the oomph to pull the thing apart to change the batteries.