What are your goals?

I would say it’s really a combination of the instances policies and their jurisdiction, and in terms of jurisdiction it also depends on where you live (e.g. you may have more protections under law if the instance is hosted in your country)

There’s also nothing stopping you from using multiple instances — siloing your interaction in different types of communities in different accounts on different instances. This may be useful if part of your privacy concerns are having all of your post / comment data on one account on one instance.

Edit: You can also use an email aliasing service to avoid even giving your email out. There are aliasing services such as Addy.io, Simplelogin (subsidiary of Proton AG), Firefox Relay (Mozilla), as well as some email providers which provide (iCloud, Proton, Mailbox.org to name a few)

Privacy and social media don’t go together. Logs of your IP are the least of your worries.

Lemmy.ml requires no email. The only person who can doxx you is yourself.

hexbear probably
does not require an email for sign-up, does not store ip addresses, and (most of the time) you get posts removed or banned for giving particularly doxxable info
though if you aren’t a communist you won’t have a good time unless you have a humiliation kink