all that dirty sweaty shit that your body drops through the glands is absorbed by your bedding. you have to change it more often like like every couple days if you sleep naked.
normally its fine to change it every 2-3 weeks
But if you have sex it's not fine to change it only every 2-3 weeks, so doesnt matter if you sleep naked or not, you have to change it every couple days.
And its more comfortable.
Changing it takes like 5mins? So its all comes down to preferences.
sleeping in just boxers is the best, because then if you have to get up in the middle of the night to go the bathroom or get some water you dont have to clumsily try and put shorts on while you're sleepy and its dark.
boxers >> naked