I love using a browser to manage Schlage keycodes instead of tediously punching numbers on each keypad. I love that my kitchen lights all come on at once instead of having to flip 5 switches all over the room. I love that I can turn on the outside lights when we're returning home late and even unlock the door as we're pulling into the driveway, so the little one can make it to the bathroom on time. I love that my outdoor lights react to both time and outdoor light conditions.
I recently bought and installed an IotaWatt, an open h/w and s/w home power monitoring system. I haven't integrated it into HA yet but I guess I only care about having a dashboard widget.
Everything is local and self-hosted. I don't have to worry about cloud rot, suspended accounts, or Internet outages.
PS, if anyone knows how to control a Mitsuibishi hyperheat heatpump through HA, I'd love to know more. It's the big missing link in the system right now.