It's nuts. I saw quite a few experienced Bitcoiners using Celsius too. They were no doubt aware of the risks, but presumably thought that should red flags arise they'd be quick and clever enough to withdraw before the ship sank.
Celsius was visibly struggling for weeks before finally tanking, so people at least had a chance to escape. But as we saw with FTX, this shit can happen extremely quickly too. How much time even passed between CZ's first tweet and FTX pausing withdrawls? 48 hours? Astonishing.