FROST is taking a private key, and splitting up into shards and setting how many of those shards are needed in order to produce a signature, in a way non of the shard holders are able to reproduce the...
Decentralized key management like FROST is actually a mature concept in cryptography. The technical novelty lies in the adaptive threshold secret sharing, but it's not a game-changer like, say, the 900 in vert skating.