there really isn't much in the way of an alternative
Bunny.net covers some of the use cases, like DNS and CDN. I think they just rolled out a WAF too.
There's also the "traditional" providers like AWS, Akamai, etc. and CDN providers like KeyCDN and CDN77.
I guess one of the appeals of Cloudflare is that it's one provider for everything, rather than having to use a few different providers?