If they had none of this smart technology, they would have still come home to the same situation. It's just that these sensors give you the ability to worry about more things while you're away.
Guy didn't even say if they enjoyed their vacation.
To challenge the author's conclusion; An AC repair person could have replaced the capacitor without interior access to the home - though it's preferred to at least have access to the thermostat.
As the Author is also from Atlanta; and we had a deep freeze last December (which we rarely do) the next step is to turn off the water automatically when water is detected (or done preventatively, though ideally you drain the pipes or keep them dripping.) *Ecobee won't know why your Ac is responding when its condensation pan is full (and tripped by a float sensor) but it could with one additional low voltage wire.
The first thing I think about a self-repairing HVAC (or, rather, an HVAC that summons a technician autonomously) is how quickly can you go from “working A/C” to “ruinously expensive”? Yeah, I think I’m gonna keep a human in the loop on this one.