In case of a house lock (as OP has), there could be an easy manual override on the inside, so at least you can get out without power or needing your phone or whatever.
Still doesn't let rescuers in, of course, but for that matter it's on par with a traditional lock which also doesn't open upon power outage.
And indeed arriving home with a flat battery in your phone (especially with the still pretty terrible battery life of modern day phones) is something that's likely to happen much more often, or at least is more likely, than the power being out or the router tripping up.