While I understand your skepticism, there are a few use cases for which I use HA which would be either painful manually, or would require alternate devices such as timers/etc:
1 - outside lights - various lights which light our home's pathway or areas we prefer to have lit at night come on automatically at sundown and turn off at sun-up.
2 - scenes; with HA, we can click one button - a switch with scene control in our case - and have the lights in the room go to a specific set point, receiver come on, select sonos, and tune in to a particular station - an activity which would conventionally require several manual steps with various input devices.
3 - notifications; with HA, I get notifications when the front door or garage doors are opened/closed.
There are several things I plan to implement:
1 - using presence detection and adjusting temps/lights/etc based upon that
2 - fan control; we are heavy users of ceiling fans, and integrating them into home automation would be a significant upgrade. Haven't found a replacement for our Minka controllers which supports zwave (or anything else).
All of this has been possible for years - usually with single vendor solutions which are very costly; HA integrates nearly all automation platforms into a single system allowing each platform's features to work together relatively seamlessly. It's a moving target, but has become very stable/reliable with recent releases.