My registrar were different before and after godaddy existed and plenty of varieties existed. I find less exist now than during GoDaddy's heyday. But less people care about domain names as they stopped becoming a lottery ticket.
My worries were paypal would take over but then came stripe.
SSL certificates were from Verisign until letsencrypt offered thek free. I didn't see Cloudflare changing that market.
Before them we had uunet and other backbone providers.
Cloudflare made their name from ddos protection attacks. They made that market.