We are never locked out. There is no key under a rock. The phone cannot get unpaired, the remote cannot be intercepted and replayed. If we are on vacation, we can call up a friend and tell them a code so they can get in.
A 9V battery lasts about three years, then it starts flashing and beeping every time you open the door for a month before dying. If you already have the right hole in the door, it takes about 20 minutes to install.
And if you're intent on breaking in, well, the windows are made of glass. Please don't do that.
I also never get locked out. Usually I key myself in with the keypad, and there's a normal key slot too. It's also powered by a 9V -- but will also indicate to HomeAssistant what the battery level is
The key isn't that connectivity is bad, the key is that it should degrade gracefully when the more advanced features fail. Wireless is down? Can't unlock with my phone, but I can still use the keypad. Battery is dead? I can still use my physical key.