Most registrars also run DNS servers as part of the fee you pay for the domain. Usually they have an API. You can just use that to implement Dynamic DNS, there are even often tools for it. Do a search for your DNS registrar and dyndns.
Afraid.org is better than DuckDNS. (DuckDNS is not reliable and have been slow or down a lot.)
But it is still American.
Let’s Encrypt is meant yo be used with automated certificate renewal using the ACME protocol. There are many clients for this. Both standalone and built into e.g. Caddy, Traefik and other software that does SSL termination.
So this specific concern doesn’t really make sense. But that doesn’t mean I really see a use case for it either, since it usually makes more sense to access resources via a host name.
That seems to be for dns resolving, not for ddns? Or am I missing something?