1 - My child is a runner. Zigbee door position sensors talk to home assistant and play sounds when a door is unlocked or opened.
2 - I'm super private. Giving people a key to my house is not something I'm comfortable with. I use Unifi Access + ESPHome + Zwave deadbolt to get the level of control I'm comfortable with. The doorbell also plays a sound in the house (in addition to the app on my phone)
3 - I have an under counter water cooler that runs way too hot. Zigbee temp sensor + Zigbee powerbar + simple exhaust fan keeps it cool.
4 - I dislike having 15 tv remotes and I have a more traditional AV setup (not sonos). I use events on the TV to control the audio (power on, volume, infer input selection)
AI has made all this a lot easier. I don't reall put a ton of effort in anymore, whereas before I'd have to fumble with configs.