in the future you just wear your work clothes to sleep and that’s normal

as far as ive been able to tell, pj’s do exist, but its a black undershirt an only evidenced in The Man Trap. naturally, Bones is the only one we see in such a state of indecency 

Spock wears a lovely periwinkle blue robe over his Starfleet Issue Sexy Muscle Mockneck Pajama Shirt

This is sexy chest hair exposing robe Picard and horrid pink pajama Beverly Crusher erasure.

hot take: they dont sleep in work clothes, they WORK in PJs

In the future all clothes are so comfy you can sleep in them