Did you notice your electronic locks all have keys for when they fail?

No, because I don't have them. I have a fake rock with a key in it and generally don't bother locking my front door anyway. But I'm lazy and cheap, not terribly interested in changing out all my locks myself or paying someone else to do it for a marginal quality of life improvement.

Still, if you have a need for locked gates, a set of combination locks all set to the same combination or keyed locks with all setup for a single key once again minimizes the need for a bunch of bulky keys.

Sure. And if you're setting up a security perimeter from first principles, that's fine. But then you add an interior gate or you need to replace a lock that's rusted through or yadda yadda life happens, and you can lose the single key design.

Case in point, my front door lock did foul a few years ago. My wife changed out the front door but didn't bother to sync it with the back door. She didn't want to bother with an electronic lock because she thought they were too expensive. So now we've got a front door that doesn't match the side door or the garage door. And we only have two keys to the new lock, one of which has been lost almost immediately.

A digital system that I can just sync from my phone would be far more appealing than juggling keys. Or staring at a key dish and trying to remember which ones actually link to which doors.