Encryption methodology and vault password

I’ve been investigating encryption software and this seems to be the best out there. However, as a novice I wanted to understand the encryption key methodology before I set myself up with this software. My very basic understanding is that if a brute force attack is performed on my vault password then the hacker will have access to my files, which will be decrypted with the hacked vault password. I see it like having a key to a safe which also unlocks the documents in the safe, in which case why encrypt the documents in the safe, as accessing the documents can only happen by breaking into the safe with the key, and so by default the encryption is also broken. Logic would follow that there is no merit in encrypting. Clearly I missing something but would like reassurance if someone can explain to me. Many thanks

Cryptomator has a brute force protection.
See here for details. Brute-force attack