Just as dumb as 2000 mile data path to a doorbell or security camera, but that still exists.

I personally haven't really thought about getting a IoT light bulb, but I would imagine you would program them to turn on when sun goes down, that shouldn't need direct connectivity and the bulbs can't tracks your phone moving aruond the house (or at least I doubt they can), so you either have to turn them on with your phone as you move along or just flip the switch or install actual movement sensors.

I'm probably completely missing the point of smart light bulbs, maybe you have actual use cases?