Cloudflare had only 100 PoPs just a few years ago. Bunny has been around 10 years, but didn't get the cash injection from Google like Cloudflare did.
If you read the article, Bunny uses Deno, CF uses a cut down version of Chromeium (each instance is like a browser tab; isolated). Thus the API difference.
But I do agree, CF is building out more of a suite.