Honestly, I don't mind them at all. the privacy policy of ao3 is still a lot better than most other sites out there, especially because they don't work with any third parties or advertisers. your info is never gonna leave their hands unless you start using third party apps to access the site (think browser extensions or apps; idk any specific examples bc I don't use any). And if you're only using the site to read, there's really nothing identifiable about you to the average user, aside from your username or anything you decide to write on your profile page. if you're really paranoid, you can always just use a VPN to hide your ip (there are a lot of free options. personally I use proton)

but bottom line, no one's gonna be able to steal your ip or anything. and if they do, big whoop, this ip user reads fic. ao3 is still one of the safest fic sites out there, both for authors and readers. authors can even lock their fics (like mine are) for extra protection. so you really don't need to worry about it!