There's a huge amount of websites that don't need a CDN (my blog has frontpaged multiple times without one). And for many (all?) of the rest you'd be fine with 3-5 regions. CDNs increase latency for low-traffic sites.
Getting angry at people for using centralized solutions is not a way to win people over to your cause, and even many people who would prefer decentralized solutions are going to pick the easy route sometimes. If you're developing a web app, maybe you want to spend your time writing app code. People only have so much time in a day.
You go ahead and play "being decentralised" with your buddies while people in the real world just mind their own business doing whatever they need to do using the current right tool for the job(in this case Cloudflare being the tool).
People in the real world, who just cheerfully do business, with zero thought of impact or consequences of their actions beyond next paycheck, have put us in this awesome economic situation, we all know and enjoy.
Surely blindly pushing, yet another corporation into position, where they can lobby virtually anything, is awesome idea. (Nothing against folks from cloudflare. They seem all right, but they will get acquired and/or change leadership at some point).
In nature, a lack of genetic diversity in a species isn't typically much of a problem until there's an extinction event, and then it can be a big problem.
You might not feel the downsides of having a huge percentage of the internet going through a single provider until it's too late to change it.
I actually quite like Cloudflare, and I don't think they're purposely doing anything nefarious (just following incentives like everyone), but I think caution is warranted.