Cloudflare Workers is a functions-as-a-service platform that runs on all the nodes of their CDN platform and works in the path of every request. Lambda@Edge, Stackpath, Fly.io are 3 similar options and there are dozens of single-region FaaS vendors. Fastly is working on a WebAssembly based compute environment.

CDNs are commodity so it's really the extra features that cause companies to move. With something like Workers that allow you to build whatever functionality you want, it actually reduces reasons to move in the first place. Also CF doesnt charge for bandwidth which is a unique advantage.