

The problem is that the biggest service Cloudflare provides is DDoS protection, and doing that requires that you have more bandwidth available than your attacker. Having enough bandwidth to withstand modern botnet powered DDoS attacks is ridiculously expensive (and it’s also a finite resource, there’s only so much backbone infrastructure). Basically it’s economically infeasible to have multiple companies providing the service Cloudflare does. You might be able to get away with two companies doing so, but it’s unlikely you could manage more than that without some of them starting to go bankrupt.
MS also recently shared that they lost 400 million Windows users. I bet most of them were Windows 10 users. This isn’t “people finally moved from 10 to 11”, this is “people finally got so fed up with Windows that they abandoned it for other options” (mostly mobile/tablet but also some Linux and OS X).