> Instead
You're misunderstanding the market.
The point of Cloudflare WAF isn't to be a main line of defense for HN readers, it's to stop the low effort automated drive-by attacks for websites that were already hosed. Like WAFs that block /wp-admin/* and instead generate a new segment.
I'd be surprised if there was a single person in the world who is going to go "oh right I should replace Cloudflare WAF and my sqli with some parameterized queries!"