I am making a distinction between a rate limited login password (which would be secure with something like “Karma27!”) and a password that protects encrypted disk data (which would need to be something like “Swipe Stapling Mortally Eloquence Obliged”). It sounds like you are planing to just use the login password for encrypted disk data encryption, which in general won’t work as the sort of thing that people use in that case can be trivially cracked.

You can do some password stretching, but that only gets you a factor of thousands improvement.

If the attacker can attack your password hashes at full speed (they get access to the disk) then you would need a fairly hefty password or a random passphrase with a fair number of words in it. That fact can make the sort of protection you seem to be hoping for impractical in many cases.