You can for example:
- Start the robo vacuum every time there's nobody in the house and tell it to stop when people are coming back - Add a voice command for said vacuum to just vacuum the kitchen or hallway - Open the curtains when it's light enough outside and put them back down when it's darker outside than inside. - Adjust light temperature and brightness based on the time of day so you won't get 1000 lumens of 6000K light blinding you when you go to the bathroom at night - Turn down the AC/heating when people aren't home and start preheating/cooling when they are nearing the house again
When everything is integrated to HA your imagination is pretty much the only limit when combining different sensors to devices.