I think looking for drunk drivers, people without insurance would be best done after 7AM at night and into the early morning.
Things such as courts run during regular hours and not showing up for that would be hell.
You'd have to be an idiot IMO to not cooperate at a legal Highway Patrol setup just as it would be driving drunk.
Gets some of the drunks off the road before they kill others.
At times they catch dealers of illegal recreational medications.
They check out that your car tire treads, lights, emissions, insurance and driver's license is all in order. That kids are in the proper child seats and that you are wearing your seat belt.
Is it a pain? Yep!
Should they do it? Yep, but never IMO in rush hours.
I did see them doing this in Rowland Heights California off an entrance to the 60 freeway during a busy time a month ago and that did NOT seem a brilliant idea.
I figure people might in their entire life get pulled into one of these once or twice. Should be no big deal, unless you are hiding something while traveling public highways.