What "use case" are you referring to? A description of a use case should not mention Bitcoin-- it should mention a problem people have which Bitcoin might be a solution.
that's easy. i need a way to store encrypted data permanently and not have to worry about my data being deleted in 2 years like gmail might do due to inactivity. it's not a huge amount of data but maybe a few kilobytes. from time to time. i need it to have 100% uptime so that anytime i need it i can get it. 24/7/365. as long as i have an internet connection...
that data might consist of anything like login/passwords to important websites or bitcoin seed phrases or anything. i know some people think it's a bad idea to store that type of thing online but hopefully people have better things to do than sit around trying to crack some AES-256 encrypted ordinal.