I don’t know but I wonder if people that have insomnia or similar difficulty falling asleep (anxiety, etc) struggle with a CPAP. I am fortunate to fall asleep very easily, usually within 3-5 minutes or even faster. And I use a CPAP (nose saddles not a full mask), and prefer it to not using one while sleeping. The way it just opens all passageways is relaxing and I think helps fall asleep even more quickly.