You don’t need to watch the video. Tom Scott/None of the interview subjects ever point out how fucked this is, but basically the story is rich sadists would put coins in boiling water and then throw them at poor children to watch them endure injury for small amounts of money as a form of entertainment.
We have a long tradition of doing silly and dangerous things. Particularly in small towns. Some have formed out of old oagan (pre-Christian traditions), some for more questionable or objectionable reasons like this one. They keep going because a lot of people have good memories of them and it becomes part of a local identity.
I watched this video, and lots of people make mention of how the tradition started, and how the pennies used to be actually hot. And why. Its referred to multiple times. Your post implies this was glossed over, but you clearly got the info from the video, so it’s not exactly hidden. Maybe that’s why OP says, “no need to watch it”, bevause they know they’re telling fibs for outrage bait?
Look up The Cooper’s Hill Cheese-Rolling and Wake. People get really hurt doing that.