If you’re not running your own server privacy policies are not even worth the pixels they’re presented on.
Literally, you’re just taking a random person’s word for it (whoever the admin is). A website is a black box, you have no idea what’s going on on the back-end.
The only way to be in complete control of your user data is to run your own server and be literally the only user on it.
Even then, any public comments you make are, you know… public.