Your electricity to servers IS a single point of failure, if all you do is depend upon the power company to reliably feed power. There is a reason that co-location centers have UPS and generator backups for power.
It may have been unthinkable to some casual observers that creating a giant single point of failure for the internet was a bad idea but it was entirely thinkable to others.
> Your electricity to servers IS a single point of failure, if all you do is depend upon the power company to reliably feed power.
I think you quite didn't got the point. The whole point is that putting together a system architecture that considers Cloudflare is a single point of failure is like designing a system architecture that considers a power supplier a single point of failure. Technically they can be considered that if you really really want to, but not only are things irredeemably broken when those failure modes are triggered but also they themselves are by far expected to be the most reliable components of your systems due to their design and SLAs that is pointless to waste time and resources mitigating such a scenario.
It may have been unthinkable to some casual observers that creating a giant single point of failure for the internet was a bad idea but it was entirely thinkable to others.