Reminds me of this article [1] from a few years back. You've got a captive audience in the car - perfect time to make a sale.
My question is - why wouldn't drivers simply cut out the middleman and offer their own boxes? I don't think that Cargo provides much added value here.
[1] https://www.forbes.com/sites/jonyoushaei/2015/02/04/the-uber...