If you're turning off lights manually through the Home app or Siri, you might be missing out on the limitless possibilities of a smart home. I rarely ever switch lights off individually. That's an old habit that people often bring along from a lifetime of using manual switches. The Home app and Siri really shine when you've set scenes that involve the whole home and multiple categories of devices.
The other habit people have carried forward is preserving energy by switching off lights. Incandescent lights were literally burning energy and turning them off when not in active use made sense. LEDs are so efficient that energy use from a single bulb is pennies and not worth concerning over single lights.
I have scenes set up that respond to activities. Most of the time, my home is acting automatically according to the status of the people in the home and my schedule. If I have work on my schedule or am in my office, my lights are brighter and whiter for better concentration. If it's after sunset and I have no work events in my schedule, my lights automatically go to soft reds and blues, stimulating relaxation.
The times in which I prompt Siri to change the lights are regarding activities: Get ready for dinner, set the scene for Cooking, watch TV, Get ready for bed, Good night. Each of these control multiple lights, set the temperature in the home and turn TVs on or off. I rarely, if ever try to turn off a light in a specific room. My scenes are set in a way that makes that light being on, make sense.
When I have someone new in my life, I've often had to retrain their habits but within a few weeks, they love it and don't want to go back.