This kind of encryption-at-rest scheme becomes an absolute necessity when cryptographic secrets have to be stored, such as 2FA TOTP secret keys or recovery codes.

Encrypting the email addresses and any Personally Identifiable Information on your users may also be a good practice, to limit which eyes can actually see the plaintext data (database provider, former developers without rotated credentials, an old backup left over..).

One issue with this though could be the inability to use the encrypted field for queries (eg: select * from users where email = 'foo@bar.com'), but OP's solution of hashing can help here: store the email encrypted, its hash in clear text, and do a query on the hash.