That seems like your much stronger older brother hitting you with your own arm and asking "why are you hitting yourself" over and over again though. Cloudflare is standing their ground with their morals, and Archive is standing their ground with their morals. Which one is right is for you to decide.
Without protecting themselves, archive.is wouldn't exist.
And given it is the subnet number being sent, NOT the IP address that people here claim, the privacy concern is fairly low (CF knows your IP address in order to deliver the DNS answer back to you and archive.is knows your IP address when you request resources).
I'll take the performance improvement that EDNS client subnet can provide.
