Pi-hole and privoxy serve separate purposes, and really could be used together.
Pi-hole is a DNS filter which prevents clients from resolving undesirable host IP addresses, so that targeted content isn’t downloaded (e.g. ad servers, tracking servers)
Privoxy goes beyond this functionality by reading and re-writing web pages to remove or replace content within a web page.
I don’t know that I would suggest either for maximum privacy.
I consider Pi-hole and Privoxy to be more about filtering content, not so much about anonymizing your browsing.
I would suggest using a VPN for privacy, and using temp-mail.org or similar disposable credential system when creating accounts on questionable websites.