Perhaps the OP was using hyperbole: it does seem more likely for reliance on external infrastructure to be disrupted by something beyond your control than for y

Perhaps the OP was using hyperbole: it does seem more likely for reliance on external infrastructure to be disrupted by something beyond your control than for your own tools to stop functioning in a way that you can't correct. There are also other effects of externalizing your tools that don't relate to continuity of uptime: levels of complexity, adaptability, security, and manageability of change all have different values for web-based and desktop software.