In S15 E71 of the Bitcoin Takeover podcast, Amir Taaki explains why he believes ZK STARKs can improve the scalability and privacy of Bitcoin.
But in order to have this type of L2, Bitcoin needs to enable the OP_CAT soft fork.
https://youtu.be/N8q04OsUJtE?si=XuLLKXniytpC4Onw