Comcast is a huge, multi-billion $ operation with global contracts and broadcasting capabilities, and > 184,000 employees globally (that's more than Google, and even MSFT).
That's not to say that we shouldn't be wary of Cloudflare for many other reasons; but that they have more influence over the Internet than one of the world's largest consumer & corporate ISPs is definitely "a take".
[0] https://www.wired.com/story/cloudflare-spectrum-iot-protecti....
After some googling, it's very unclear how popular their CDN service is. Based on some of their marketing, seems like it might be focussed more on the video delivery side, which would also make sense given that it's Comcast. (If it indeed is an enterprise video delivery service, they may only have a handful of very large customers)
If this is accurate, it seems like Comcast also controls the data end-to-end (being both an ISP and CDN).
[0] https://www.comcasttechnologysolutions.com/
[1] https://www.comcasttechnologysolutions.com/sites/default/fil...