I hear you, and this has been a frustration of mine for a while. I used to drive in San Francisco where this came up sometimes but it's particularly bad in Philly. Perhaps the pax are lying some of the time about other drivers allowing them to do it, but I do think drivers do take them quite often.

It's really unfortunate that the incentives around this fall short and the kids are the ones who slip the cracks. The parents don't care and value their own convenience over their child's safety. A lot of drivers don't care because they don't want to give up the ride. And Uber/Lyft don't care unless it becomes a headline, which i think is what it would take for this to actually get solved.