Nowadays, depending on the legislation of wherever you live, there might be requirements for a minimum amount of information you need to log and preserve for a minimum amount of time, and restrictions on what information you can’t log and need to remove after a certain amount of time, or upon request provide to users, delete, or save apart.
You're not wrong, but I don't think anyone is actually trying to enforce this for small-scale things like personal websites or lemmy instances.