I used to think this also, but now respectfully disagree. I dislike the standard earpods and thought I would not like airpods.
However when I tried the airpods, I was pleasantly surprised. They stay in my ears much better. In fact, they never fall out, including while exercising. They are the best.
I can only speculate the wires add just enough weight or resistance to make them fall out occasionally.
I recommend trying the airpods, even if earpods don't do it for you.
It’s true and been reflected in many reviews and hands on experiences with AirPods. Because if the lack of wires, they fit and stay in ear much better. No wire to tug on them.