It is important to understand, we don't help you to fall asleep. This isn't an insomnia device. We increase the efficiency of deep sleep specifically, and it is most effective on people who already have lower/less deep sleep.
> Nothing in the existing research suggests this to be the case
Was it considered?
However, I will say that there is now more than a decade of research into slow-wave enhancement, and multiple studies looking at safety, and efficacy.
If dependency is a concern, it's somewhat the opposite. We're stimulating a sleep function that naturally degrades as we age, and trying to get it to maintain it's power. So you naturally lose this ability.
Note: we can't create slow waves (yet) we can only increase what is already there.
In the same way brain kindling works for seizures, my guess is sleep is a learnable skill, and once the pathway is etched it sticks around.
There will be other discoveries in the future, who knows what we'll learn, but the current body of knowledge (and there is a decent amount of it) does not suggest a learned response to be the case.
Furthermore, the sleep we stimulate is deep sleep, which naturally degrades as we age, which perhaps suggests that it isn't a learned response, or else why would we see a reduction with age.