I guess this, lowers the barrier to entry for this extremely specific niche?

Domain registration is already API driven and has been for decades. The most sophisticated domain name investors (or "domain farms") go as far as to own registrars directly so they have instant access to the registries. Nobody involved in domains would use Cloudflare's product because they already have and have had automations for decades.

For example, DropCatch (NameBright) own over 1,000 different registrars so that they have over 1,000 direct routes to Verisign's .com registry. GName are a new player in the space, approaching 1,000 registrars. The amount these companies spend on their registrar licensing alone is many millions of dollars[1].

Cloudflare's product adds nothing new to the world of domains. Anyone has been able to go to OpenSRS and sign up as a reseller with API access for over 20 years.

[1] The majority of ICANN's registrar revenue comes from just a few companies that own thousands of registrars collectively: https://www.iana.org/assignments/registrar-ids/registrar-ids... cmd + f "DropCatch" and "GName"