It takes a higher computational power to reverse the private key to public key operation or compute private key from signature.
I think it’s a typo mistake here, reversing or decryption of this key pair will actually be public key back to the private which is the encryption
I'm talking about the Elliptic Curve Point Multiplication operation where you compute the public key from private key. This is irreversible. Or in another words you need an impossible amount of computational power to reverse the "private key to public key" operation.
In technical terms that is to solve Elliptic Curve Discrete Logarithm Problem or ECDLP for short.
You are also using the term "decryption" wrong. Decryption demands a cipher text (encrypted message using a password).