I gave up on account creation for some projects and store the user preferences in local storage. It is an amazingly annoying feature in that it is very hard for the user to erase the data but you can't smoke your cigar and have it too.
I am uninterested in creating an account to use an llm service, and doubly uninterested in giving one my email address.
These are separate concerns.
For instance, HN allows account creation without providing an email.
Wondering about this I had several horrifying thoughts. Somewhat palletable seems to add a hosting account with a subdomain so that one can share conversations and other ai creations, upload other things and use them for future reference. That way visitors can adjust to the content being machine generated.