There is little about this that is specific to disc brakes. I'm not sure what the point is.

"Things can go wrong. Be prepared." ?

Tldr it was his own fault for rising with pads way past their due, says it himself basically.

I've got 4 bikes with disc brakes. Only 1 had ever had some disc rubbing.

I'm curious how often this happens with properly maintained brakes.

Unless you're very unlucky, your worst case braking-related scenario is that you run the pads too low

Well guess what, when you're unlucky with those, better bring a spare wheel with you. 🫠

https://hessen.social/@goto/117285812544593169

I know someone who crashed and cut an artery on a disc brake. But I assume that's extremely uncommon.