Client devices, I think - filtering that happens transparently and without an easy way to disable is just asking for problems - I couldn't deal with having to log in to the DNS management console every time when a website notices that ads didn't load and therefore doesn't display content. I don't think we're at a point where privacy can be guaranteed by technology choices - it's all about behavior of end users (like avoiding websites which block content if ads don't load ;-)

Is it possible these privacy/filtering DNS services like NextDNS come without a performance hit? Imagine setting it up and forgetting about it, and discovering later that all your DNS queries happened with a substantial lag - it's like realizing you've been driving with a hand brake on