I've never actually gone and confirmed what specifically hinges on ECC, just know I've read in various places that it's everything from banks and credit cards to nuclear missiles.

The typical answer is that quantum will get it. If quantum takes out ECC it isn't like the encryption on the things that aren't ECC will save us. Very few quantum ready claims out there so far.

Right, people FUD that quantum is gonna break ecc. And if that happens I guess you're saying breaking the rest follows quickly..don't know if that's true. Thought I'd read a bit about other schemes that are more resistant, always involving hashes somehow, but gather they're not widely used. Also, could imagine there are some different-enough widely adopted schemes that aren't ECC, don't involve hashes (so not quantum resistant the way I loosely understand that stuff to work), but wouldn't necessarily be a simple extension of a ecc-breaking quantum algo.

ECC being cracked by surprise really would be end of the world type shit

Oh? Well, hey - I guess that means we’re past the “what if the entire internet goes down?” argument. Progress?

Few, but not zero

Post-quantum cryptography - Wikipedia

Right, but they aren't being used. Not for banking or anything important really.