> Garage door spring broke or power is out, and battery died on your electronic house lock? You're not getting in.
How, exactly, would this happen simultaneously? Any reasonable system should alert you when batteries in your locks are running low. Unless you brazenly disregard those warnings (since, the low battery at least on mine means you still have... weeks left of battery), you will always have access. Also, with multiple entry-points into the house, you'd need ALL door locks to have their batteries die simultaneously. And the power to be out. That's a level of redundancy that is just unreasonable.
> Actually had that conversation about the house with my wife when she didn't carry house keys: do you want to find yourself stuck out of the house while the pets freeze or boil because you didn't just carry a damned key?
In what world would your pets die because you got locked out of the house? You should have AC/heating... and in some sort of power outage event (which, also, would require you to not be home either), your pets are certainly not going to freeze/overheat immediately. In such a crazy unrealistic scenario, breaking a window or drilling out a lock is a straightforward solution. But also, that would require so many multiple events to happen simultaneously (to get to needing to break a window) that it will never reasonably happen.