If you register a domain with Cloudflare or Route 53, and that service goes down, do your records stay active in the DNS servers? What if the DNS servers go down, I know a lot of people use 8.8.8.8, so if Google’s server goes down, then DNS fails?
What are the potential point of failures for having your own domain?
It depends on the implementation and configuration of the resolver you’re asking. RFC 8767 allows serving stale data, if the TTL has expired but new data cannot be fetched.