There is a difference between a weakness and complete breakage. You might have a small edge over brute force, but not enough to reverse any public key. This acts like a canary for weaknesses.

some people just want the cred though. their name will be immortal and live through history as being something, or some such nonsense that feeds an ego.

also, if you were the type that thinks bitcoin is lame, this could be a way of undermining the concept to the point that people no longer use it because it's not secure as it was touted

What you would do is claim the prize slightly ahead of schedule and wait to be slightly ahead of schedule for the next one.

What would you do?

I'd claim the prize, sell for USD, then watch BTC crash

It would crash before you could sell it. Guarantee major market makers are watching these wallets specifically, and autonomously.

So if someone figures out how to do it, they then effectively have a button that destroys a massive amount of wealth worldwide owned by a pretty specific group of people? That's fascinating, with billions of dollars at stake people would absolutely kill for that, not to mention the governments that use crypto on a macro scale for avoiding sanctions etc. Would probably make a really good thriller.

My theory: The wealth would probably effectively transfer to holders of other currencies. You aren’t really destroying wealth by destroying currency; the supply of stuff is still available. Just now the demand for it from crypto-holders is gone, so it’d get cheaper for USD-holders.