Reply to post:

but Uber and others make up a chunk of movement that they can’t track.

Really? With several ANPR systems (the ones we know of) in action?

You need to develop some abilities seen in Sci Fi movies (f.e Clingon warbird(*) cloak) to move from A to B in London without leaving a detailed record of your movements.

(*)_{I do not want to even try to guess what the Congestion charge and Green Crime charge will be for that one}