In theory even a single company service could be distributed, so only a fraction of websites would be affected, thus it's not a necessity to be a single point of failure. So I still don't like this argument "you see what happens when over half of the internet relies on Cloudflare". And yes, I'm writing this as a Cloudflare user whose blog is now down because of this. Cloudflare is still convenient and accessible for many people, no wonder why it's so popular.
But, yeah, it's still a horrible outage, much worse than the Amazon one.