Domain service - name registry - is a weird market because it includes cross-subsidizing businesses and the information has value (and people will pay for anonymity to avoid hassle), so buy decisions aren't just price/performance.
Google and Cloudflare can offer it near cost just to build goodwill in their clients (i.e., to save them from predation). Cloudflare promises for renewals to only pass through their costs, which makes sense (they make back their customer acquisition cost on the first purchase).
What's the business model of others like porkbun? By hypothesis, you have to pay more to go without the cross-subsidy. If cost is on par, then you might expect them to be marketing the information or to customers somehow. Perhaps just making it back on anonymity charges?
At a minimum, the company would need to have some real reputational concerns about maintaining good relations with customers. E.g., with porkbun, it's super-cute in an ostensibly-benign jurisdiction, but it's a completely hidden LLC who's privacy concerns seem limited only to WHOIS anonymity. What exactly prevents them (or any successor in interest) from misusing the information they have?
On the internet, associating real people with IP's will always be a key goal of governments and criminals, and yet domain name services are a free-for-all with no underlying privacy guarantees.