If Uber suffered hard enough, do you think VC money might shift or otherwise move into Lyft? Even if all of Uber's VC money vaporized? Billionaires gotta make a living too.
Probably not. The main reason Uber got so much VC funding is because they promised investors that they would be treated as a technology services company, which would allow them to ignore various laws and regulations taxi companies are subject to and eventually drive them out of business to become a monopoly.
If Uber fails at executing this business model, it's not clear why investors would take a second chance with another company of the same type.
Where does the profit come from, and does it go to the VC investors?