I think it was Cloudflare but you might be right that it was Google - either way, I'm just using default DNS from my ISP, and only had issues for the past few weeks (and only with that one domain, .is not the others - while iirc the known problem with one major DNS provider was due to some choice of DNS setting that means all archive.today domains are affected not just one/some.)
No matter which upstream DNS you use, if you have a local resolver, you might be able to configure it to resolve archive domains with google's dns, which has consistently worked for me for years.
If you use dnsmasq (either bundled inside pihole or not), this line in its config will make it use google dns to resolve archive.is and archive.ph:
server=/archive.is/archive.ph/8.8.8.8
I started using blocky instead of pihole recently, and I have this in my blocky config.yaml to do the same thing:
