Your infra is relying on an ISP and colo and the power company and maybe even the Post Office. You're always relying on something that's not you. Personally I'd rely on pre-paid AWS. If all of us-east-1 goes down for days then we probably have bigger problems.

That's what I thought; this tool is "kicking the can" to whatever third party service you're using. So, it's essentially just a tool that will ping stuff for you in a slightly more convienent way?

It's a cloudification of dead man's switch.

Now two isolated systems have to fail. Redundancy is fault tolerant. Nothing is fault proof.