A similar 'shake up' has happened in the tourist accommodation industry. Air B'n'B has made it possible for people to rent their cottages to vacationers without having to pay for ads to attract business.
The same problems occur in each platform.
Due to numerous health and safety measures, which licenced cabs and tourist properties have to fulfill or they expose themselves to government fines, prices are higher in the 'industry'. There are other economic factors that determine pricing as well that are not part of private cottage rental, or renting out the room that has been vacated by a child who has gone off to college.
Buyer beware...you get what you pay for. Hope saving a couple of bucks doesn't cost you more in the long run...