I've been using this same microSD card throughout most of my development this year. You can assume that it's been fairly abused in sheer number of reads/writes.
That said, I think it's just... sort of... died. Having replaced it this morning, the system is coming up happily and without the usual fits each morning.
The last two weeks have been one problem or another upon first (few) boot attempts.
What's odd is the sheer variety of hiccups and errors that this seemingly caused. It's not as if it presented itself as the same problem twice, to be honest. I don't recall seeing a suggestion to
ext4 partition so I don't think this is technically file system corruption.
- Replaced the Raspberry Pi 3B ("yay, it's behaving... that must have been it")
- Replaced the 5V adapter ("ah, it was the adapter that was the problem")
- Replaced the microSD card ("grumble... grumble...")
Earlier, I was getting things like...
- freeze-up at the four-raspberries stage of the boot
- freeze-up at some odd stage of booting but before networking was up
- failure to present a Window provider to Kivy
Unable to handle kernel NULL pointer dereference at virtual address 0000001b
Unable to handle kernel paging request at virtual address e24dd028
- and many more