My guess is the shape of the cap, and maybe even a bit to do with the material (ime pop-off caps are a weaker plastic to allow them to deform around the bottle lip). Screw top plastic bottles have deeper caps than pop-off glass bottle caps.

Thus when stored the inside surface of the pop-off cap has more chance to rub against other surfaces and create plastic dust, and being a weaker plastic it may gouge more easily as well.

My dad recent got a decent payout for being the internationally trafficked childhood victim of one of these unwed mother homes…

Not worth his lifetime of trauma, nor the issues that came with being sold at age 4 to a “keeping up appearances” family that sent him away to boarding school on top of everything…

But it’s something… he’s mid 70s, so you know, totally enough time to use the money.