"research has shown that people sleeping in an upright position have sleep that is poor in quality compared to those who sleep in a horizontal position"

That is "True".

There are various stages of sleep, one of them is REM or Rapid Eye Movement stage, when we enter this stage of active sleep, and our muscles lose tone, making it hard to keep up a seated position. Accordingly, when we rest upright, our necks tend to strain or drop to the other side, which can cause pain. There are other issues as well but this should also be noted that in certain conditions an individual needs to sleep in upright position.

acid rain is the answer

answer; self_ disclosure;