the purpose of hdparm --security-set-pass when erasing an SSD

Hi,

I've got a pretty simple question to which I wasn't able to find an answer on the internet: what is the logic of setting a password in order to securely erase the SSD? The SSD has to be locked with a password in order to for the security erase to work. Does it actually use that password somehow in the erasing alghoritm? Or to put it differently: does it matter how complex the password is if you're going to erase the SSD anyhow?

Thanks!