Comment by neop1x

It's not only centralization in the sense your website will be down if they are down but it is also a centralized MITM proxy. If you transfer sensitive data like chats over cloudflare-"protected" endpoints, you also allow CF to transparently read and analyze it in plain-text. It must be very easy for state agencies to spy on the internet nowadays, they woukd just ask CF to redirect traffic to them.