Principally yes, but it also aims to protect against evesdroppers for example. Many usecases want to keep the algorithm being invoked secret (by having it run on a computer the requester does not have access to)

Anyways, the reason i asked is because the grandparent said "attacker can memorize the input and output", which is not something the entity doing the computation can do, as they only see the encrypted text, and encrypted values never repeat (or only with negligible probability) even if the plaintext they are encrypting are the same.

The end user entity on the other hand, could try (in theory, not practically) every single value, memorize it, and recreate the secret function. So if the attacker in this scenario is the entity encrypting/decrypting the data, some of the grandparent's post makes more sense.

Doesn’t that threat model defeat the purpose of the algorithm leaks?