Somebody else asked this but deleted before i could respond, so i am glad you asked.

Centralized DDOS protection and DDOS seem to be two sides of the same coin, so i dont understand what the distinction would entail.

edit: You could argue that DDOS is an equal opportunity tool, while the threat of getting kicked off cloudflare is reserved for a selected few. So the difference would be which is more at threat of getting exploited. Hope that helps.