Sleep hygiene technically doesn’t matter right?

Every sleep doctor talks about sleep hygiene. Not laying in bed if it isn’t for sleep, no screen time, no tv, getting enough early morning sunlight, get exercise etc and they will give you sleeping pills. But what about bedridden people in the hospital or nursing home? They get no sunlight. If so very little. They are mostly bedridden. All they do is watch TV and they still sleep. Anyone else ever thought about that? My theory is either you have a problem with insomnia or you don’t and it has nothing to do with what you do.