Yes.

You can always use third-party DNS if that's what you wish to do. That should be a supported configuration with ~any registrar (and if it isn't, avoid them).

You can run your own (first-party!) authoritative nameserver(s) for your domain, if you want to, and you can even do this on hardware that you can see and kick. A nameserver isn't particularly hard to set up in a sensible fashion.

However it happens, eliminating Cloudflare's DNS from the equation is easy. The TLD nameservers (for .com or .net or whatever) will cheerfully direct resolvers towards whatever nameserver(s) you specified as part of your domain registration.

After that, when Cloudflare DNS dies on any random Tuesday afternoon, your domain will still work. (Maybe it won't work for those using Cloudflare's 1.1.1.1, but those people may have bigger issues on that particular Tuesday.)