I'm not uncircumcised, but my husband is. As I have very intimate knowledge of his penis, I feel like I'm qualified to respond.
The only time the hubby is comfortable with his foreskin rolled back for any length of time is during sex—and even then, the vast majority of the time his penis is in my mouth, so it's not like it's exposed for that long.

After he climaxes and goes soft, if I leave him uncovered, he automatically reaches down and slides his foreskin back over his glans. Usually I do this for him, but sometimes I'll leave it exposed just to see if he covers himself back up. He
always does. So I think it goes without saying then when he's wearing clothing of any sort, the head of his penis is always nice and snug and tucked away inside his foreskin.
A close friend of mine (Hispanic and in his mid-60s) is also uncut. We have had more conversations about his penis than I ever imagined we would have.

Anyway, he confided in me that his glans is
extremely sensitive. Even the thought of it being exposed against fabric, even for a short period of time, would be absolutely excruciating. Because of this extreme sensitivity, he wishes he had been circumcised when he was younger; but he would never consider doing it now.
The purpose of the foreskin is to protect the head of the penis and keep it extra sensitive, smooth, and moist. Keeping it retracted for any length of time would serve to toughen up or desensitize the glans. Of course, in some instances this could be beneficial; but by and large you don't want to go out of the way to desensitize your penis!