I think cloudflare has billions worth of incentives to be reliable however they can slip up, it happens and that's why centralization is bad.
However, I would say that the effect of this outage on customer retention will be (relatively) smaller than it would be for a smaller CDN.
Cloudflare just caused a massive internet outage costing millions of dollars worldwide, in part due to a very sloppy mistake that definitely ought to have been prevented (using Rust's “unwrap” in production ). Let's see how many customers they lose because of that and we'll see how big are their incentives. (If you look at the evolution of their share value, it doesn't look like the incident terrified their shareholders at least…)