Yeah and then you get paid 350k at 24. I’m glad we’re in an industry where you can become incredibly well paid by spending a few months studying for a standardised, albeit unofficial, test. Much better than the CFA investment bankers, accountants, law school grads, etc.

Wow I wish I was paid anything near that. I don't know how many outside of the US get that well paid.

This. And there are plenty of high paying companies that will respect your time better than FAANG.

I disagree with this - here's my experience. I started training for competitive programming in college. One semester in particular I spent 20-30 hours a week training, and some of my grades suffered as a result. But I got a lot better at algorithms. Years later, what skills do I remember from college? Very little, but I definitely remember the algorithms. Further, converting specifications to code and general problem solving became noticeably easier after this period. As a result, the jobs I've had have centered on problem-solving and interesting technical challenges. I'm always surprised when an idea from that period suddenly proves itself useful.

Also, even if training for algorithms questions was purely a matter of signaling with no positive externalities - it's actually a much faster and easier process than getting another degree, which is a common alternative.

TL;DR If you put in the time, it can absolutely change your trajectory in ways that you might like a lot. If you don't, how will you know?