CDNs and reverse proxies are important part of internet infrastructure. Problem here is not that webservers use CloudFlare, but that use only CloudFlare.
Let's assume that i could easily use multiple CDNs/proxies and put them all in my DNS record. It would be nice if web browsers would use happy-eyeballs like logic to switch between multiple IP addresses, but i don't think this is default behavior with multiple A/AAAA records.