I have a keyless, non-IoT deadbolt (number pad with access code). It's hugely more convenient and more pleasant to use than traditional keys. One of those things that you don't really realize until you have one. I never worry about having house keys. I can pop in and out of the house on short jaunts with much less friction. I can give people access to my home without coordinating handing over keys. I don't have to go through the clumsy and annoying process of getting keys out, sticking them in the lock, turning them, turning them back, taking them out, and putting them back in my pocket just to walk through a door. It seems trivial but it really does noticeably improve quality of life.
1. If you forget/lose your keys. If you still have your phone with you, then you can use that to unlock it, or if you set up a passcode ahead of time, you can use that too.
2. If you're having someone over and you're OK with them letting themselves in since it'd be inconvenient for you to meet them to let them in.
I've had both of these situations happen to me. Granted, the solution shouldn't cost $700, but a lock you can open with your phone and also email/text someone a time-limited passcode for is useful.