What's even more astonishing is that when someone creates a new Crypto wallet, it creates an obscenely long random number as a seed, and just starts using it. As long as the number is sufficiently random, the chance that someone else has generated the same random number is so small as to be functionally zero. So you don't have to ask for anyone's permission first before using Crypto. You only have to ask the Universe for some of its entropy, and off you go.

It's the same math of large numbers that leads us to conclude that every time we shuffle a deck of cards, the result is a deck that nobody in the history of the Universe has ever seen before. 52! is an insanely large number, which is on the order of 10^67 .

https://quantumbase.com/how-unique-is-a-random-shuffle/

The math behind Crypto is sound, and ensures that everyone's wallets stay secure. Noone but their owners can move funds out of their wallets, and once a transaction is sufficiently confirmed, it can't be undone. The only real threat to this is Quantum Computing, which might be used someday to Crack the relationship between public and private keys which is unassailable now. We'll see whether the people who run these Crypto networks are able to change their algorithms to be Quantum resistant in rhe future.