I don't have much to add about the title except to suggest taking it with a hint of skepticism. Personally, I have a strong affinity for Cloudflare. It has consistently come to my rescue on numerous occasions. I haven't encountered any issues with speed while using their services. It's possible that my fast ISP plays a role, or perhaps the original poster needs to optimize their CF services. However, I believe it's unfair to make a straightforward claim that "They are slow" without considering potential biases. The performance of the services will always vary, and ultimately, the maximum output will depend on the specifics (end point?)