[simonblack]

The main benefit as I see it, is that pyjamas/nightshirts/nighties/socks/etc get restricted by friction against the sheets and other bed coverings. Every time you move, you probably need to wake enough to overcome that friction.

I gradually progressed through my 20s and thirties trying to get more comfortable at night, mainly by removing tops or bottoms of pyjamas. Then I had a brief phase of using a night-shirt, but that was just as unsuccessful.

Finally, around the age of 40, I took the bold (at the time) step of sleeping naked. Much better, much more comfortable. I have slept like that for decades since.