Re: "Drivers should be compensated [..] from the moment they log on and off the app"
"You get paid for your work, not for being logged on"
Good point. Get employees to wear a tracker, log their activities on screen and then don't pay them while they're not working desk. Having a piss - don't get paid. Grabbing a coffee - don't get paid. Walking to a meeting - don't get paid. Responding to an urgent mail from the other half - don't get paid. Waiting for your boss to clear out of the meeting room you've booked - don't get paid. Being interviewed by HR for whining about the tracker - don't get paid. Etc.*
Everyone knows one or two people who clock in then spend the next hour or so making coffee, doing the chat rounds, sorting their personal mail, etc. before actually getting down to work - no different from from someone logging on to Uber and then not doing any jobs. Uber needs to do like every company and manage it. If someone can log on to the Uber app and not work for hours then that's Uber's fault for mismanaging their labour force or having too many drivers for the customers they're likely to get. The "gig' economy lets employers dump all the uncertainty around management and load all the risk on the employees, which would be fine if the employees were getting the thick end of the £wedge to compensate for the risk, but they're not. If Uber want to trade on the fast availability that comes from having a surplus of drivers online they they should pay for it and put the fares up or do like other companies do and match resources against demand.
* Yeah - Amazon - I know.