Doing favours for friends is very tax efficient. You basically pay no tax when you give or receive a favour. And let's face it, even though sometimes you might

Doing favours for friends is very tax efficient. You basically pay no tax when you give or receive a favour. And let's face it, even though sometimes you might pay a friend to babysit or whatever it is cash in hand and no tax. But the sharing economy requires you to pay from your after tax salary to someone else, who then pays tax on that before they get their pay. On top of that the rent seeker (uber, etc.) has to take their slice. So it's a low paid marginal business once you are being paid.