I've only seen that in Japan so far but both there and in New York I've seen the long leash where each child is clipped on with a harness. But these are for daycares and school field trips... clearly ripe for disruption. What parents need is an app like Uber for when they just need to go somewhere now...
I suspect the liability & trust problems would be insurmountable though. I'd pay up into the high hundreds per month to not have the time-suck of pick up & drop off constantly...
Perhaps parents could pool enough money together to actually keep a full-time chauffeur around somehow. Scheduling would be rather dicey though.
Found this but for at-home babysitters: https://angel.co/chaperone Don't know if telling people to "think Tinder" for the UI is the best association though.
I am not a parent, but I think we're losing some brightness in our future if we can't resolve trust issues that lie in the way of better services for parents and children. Lots to think about...