All travelers do but all border inspection people do not. Or if they do, they apply their discretion very unevenly in some Very Interesting Ways.
I've watched it happen twice since COVID, both times traveling abroad for work and coming back into the United States with coworkers (different coworkers each trip) who are not nearly as pale as I am. Neither of us had Global Entry or anything like that back then. Both times, I got waved through with barely a glance and my US-passport-holding coworker got grilled. "Where do you live", "why did you go on this trip", "who do you work for", and so on.
To reiterate: All of us are citizens, all of us were born here, and we were taking the exact same trips at the exact same times coming back with the usual things you take with you on a business trip.
Anecdotes from friends who are darker than a sheet of printer paper tell me this situation has not improved.
