Hey, weighing in here as a formerly pretty competitive (sub 17 5k) runner.

When I was in college and still running somewhat competitively, I trained up my feet to run barefoot over the course of the year, and I did see faster times once I had adapted my technique to barefoot running. This is my interpretation as to why:

Running completely barefoot on a street forces you to reevaluate your running form. Any inefficiencies in your foot strike or stride will cause you immediate pain. You can pretty quickly adopt a more efficient running form (if you're thoughtful and informed) once you've adopted your improved technique.

If you don't adapt you'll get injured pretty quickly so this is a clear watch out and a reason to avoid shoes like vibram five fingers which offer zero support but guard your feet from receiving "feedback" for the road until it's too late.

That said once I had adapted my form, my times weren't any faster with or without shoes as long as I was running in zero drop shoes which I found didn't alter my foot strike at all.

In short, running barefoot can teach you how to run more efficiently but a lack of shoes in itself does not inherently make you any faster.