Cloudflare is egregiously bad because of its marketing strategy. It tried to get everyone with any small website to use it, by selling a vague notion of security and charging no monetary price, and it worked. They'll even sell you a domain name to increase lockin. Many people recommend getting domains from cloudflare because apparently they're cheap.
Akamai, Fastly, etc only take big customers who know what they're doing. You need to sign a proper contract with them. They aren't low-friction.
Ideally yes, the TLS termination does not need to happen for caching purposes. Challenge is that in practice every business wants to be sticky and try to provide more functionalities which do require TLS termination. Most people either trust CDN's or they do not understand MitM so it does not concerns them. Plus they are getting certificate management and DDOS prevention capabilities.