This is probably an idea someone has already discussed, but…
I really like the idea of occupancy sensors but they always seem to need you to move in the room too much to make them work. Now that all phones have BLE going most of the time it seems like you could use this to sense if someone is in a room or not. This is what I believe Tesla uses to make their phone key work.
The idea is that if a switch could register a MAC address for a device it could sense if that user was within a certain range of the device. Since most switches are close to a doorway, this might help with the trigger for on being close and off being much further away. You could even trigger user specific scenes.
This wouldn’t work for all rooms since the proximity trigger could occur on the other side of a wall from you, but for many rooms it would work pretty well. If you could directionally shield it, that could help too (is that a thing?). This might also require an app on the phone to work, but that wouldn’t be hard to do.
Also an interesting thought would be security. You could sense MAC addresses not registered. If you have a break in you would have the MAC address of the burglar. Not sure the court would admit this evidence though