You reminded me of this old joke:

> Two economists walk down a road and they see a twenty dollar bill lying on the side-walk. One of them asks “is that a twenty dollar bill?” Then the other one answers “It can’t be, because someone would have picked it up already,” and they keep walking.

The drivers are sitting 10 feet away, they’re not just abandoning them.

The article described drivers as walking up and syncing to them to get a job, so they're not always sitting by the phones.

Seems like a trivial extension to the story that one person is sitting nearby keeping an eye on the phone. The advantage still holds, since all the other drivers in the group can spread out.