Collecting watches isn't a hobby, it's pure consumerism. Sure many hobbies have (recently?) gotten way more people spending top dollars for no reason but with watch collecting there's nothing else. You're not tweaking the dials, you don't know how to make the watch, you just watch it and wear it while a technologically superior version is 500 times cheaper. There's also no natural shortage of them, they can make a trillion of these watches.

At least with cars or audio equipment there's some marginal benefits once you get to crazy numbers, not the case with watches.