CloudFlare can be used for dns registration and management as well as ddos protection, ssl cert issuance, origin hiding, static hosting, edge computing, and more, all in the free tier. If you use something like namecheap, you may find the dns resolvers aren’t super great - eg. Changing a record may take 30 mins to propagate because they use higher TTLs by default, whereas CloudFlare’s anycast dns network usually propagates a DNS change where its testable on any network within 60 seconds. The downside of using CloudFlare for both your registrar and operationally is if they ever have an outage at the registrar tier you won’t be able to route to new nameservers. If you’re worried about that you can buy your domain through someone else but point at CloudFlare’s nameservers.