What you're suggesting pretty much can't be done, in terms of orbital mechanics. In order to achieve global coverage from LEO satellites, they need to be in a bunch of different orbital planes.
(And also, in LEO it takes a lot of fuel to do orbital plane changes.)
So that means it's impossible for a Starship upper stage to pick up more than a few of them for return.
It makes more fiscal sense to just let them burn up in the atmosphere and let others pay the externalities.