Unless you are using Cloudflare's specialized security services, CDN is pretty interchangeable and easy to switch between. You can ever do dynamic DNS things to use multiple CDNs at the same time and shift different traffic segments onto different providers if you are into that sort of things, or tier one CDN behind another to act as a mid tier.
I don't really understand why the decentralized internet folks harp on CDNs because they will be very required if they ever get their way since by definition, if everyone is running small to medium, highly distributed sites, then you aren't likely to have a point of presence near most users and that will be poor user experience.
My guess is that most people have only heard of Akamai or Cloudflare so they automatically associate CDN with huge companies, but the reality is that the CDN space is highly competitive and decentralized. Just off the top of my head there's at least a dozen providers I would consider tier 1, several dozen I would classify as medium sized or targeted at niche audiences, and probably hundreds of small providers, not to mention just about every large telco operates their own CDN now.
https://en.wikipedia.org/wiki/Content_delivery_network#Notab...