Arisu 🏳️🌈, it's a KDF, not a hash function. It serves a different purpose. Password-based key derivation functions usually are deliberately computationally expensive as their output is then used as an encryption key so it's extremely important to protect against brute forcing. Some take literally seconds. Why would you put this much load on a server though?
@grishka because of improved security. i don't know enough about security to say anything, but searching got me to think the security benefits are worth it.