As a counterpoint, yet completely anecdotal, point of view, I've had none of the issues you describe.

Once I install a Z-wave light switch and add it to my hub (a very simple process) there is virtually no maintenance. I rarely use the phone app to control things but I reliably get push notifications for things I want to know about (forgot to lock the front door, garage door being opened unexpected, door unlocked by specific people, etc.).

Most of my interaction happens via Alex and it basically just works.