DDoS attack primary goal is to make the target server unreacheable for users. It is in the name - Distributed Denial of Service attack. If user can't access the service, i.e. denied of service, the goal of DDoS is reached. Cloudflare prevents only the flooding of server with a storm of requests. And it prevents it by not forwarding them to the server. Yes, target server continue to work, but nobody could access it, because Cloudflare drop requests. In any case user denied from service.

So, such DDoS "prevention" have no sense at all, since users still denied from service. In the best case, only thing server owner get is lower incoming traffic during DDoS, and that's all.

Marketing lies of cloudflare does not make the whole thing work. Just swindle server owners into selling all their users to the hands of that shitty BigBrother company that will mitm even into SSL connections (yes, in any mode Cloudflare decrypt trafic from target server and encrypt trafic for users with their own certificate - check lock icon in your URL bar for conspiracies.win - it will be Cloudflare certificate).

I would not be surprised if it will be revealed that cloudflare organize and do all that DDoS attacks on the sites that will never really could become a target of real DDoS just to convince site owners to buy into cloudflare man-in-the-middle crap.