If there's a fitting competitor worth switching to.

Plus most people don't get blamed when AWS (or to a lesser extent Cloudflare) goes down, since everyone knows more than half the world is down, so there's not an urgent motivation to develop multi-vendor capability.

Can't say that when it is a time critical service such as hospitals, banks, financial institutions or air-traffic control services.

Only a fool would build an architecture for critical air-traffic with Cloudflare as a SPoF.

My point still stands.

Having no backup / contingency plan even if any third party system goes down on a time critical service means that you want to risk another disaster around the corner.

In those industries, accepting to wait for them for a "day or two" is not only unacceptable, it isn't even an option.