This is such a bullshit argument. What you're basically saying is people wouldn't have driven their cars and stayed at Home if Uber wasn't a thing. That's such an inane argument. Ridesharing is good and reduces overall traffic. It doesn't make people go out more than they require. No one says "it's a good day to Uber today ".
I've read a dozen studies so far that indicate Uber increases traffic and congestion in cities it operates in. Quite a lot, actually. Increasing commute times by 40% or more in some of the studies. Venture capital is paying people to idle around the city, clogging the roads. It's a sort of denial of service attack.
"Uber and Lyft Admit They're Making Traffic Worse"
This is the normal outcome of more people going to more places. Ridesharing definitely increased the total amount of people taking cars that didn't before from a lack of options, but that's minor in terms of general population growth.
Traffic always increases over time, that's a natural thing that cities need to plan for. It's great motivation to build public transportation instead of complaining about Uber helping people get around.
You didn't answer the core point. People don't sit at home if there are no taxis. That's never happened. And if cyclists take cars now, it's probably because it's safer to do so than riding around traffic. These aren't bad things.
Go back to pre-Uber. No one called expensive taxis and used private cars, including the cyclists for non trivial distances. Uber came and solved the first step. Maybe some cyclists even take it for trivial distances. But that's blaming Uber for a good product and promoting a protectionsist scheme. Rather if you want more pedestrians and cycling, have more infrastructure and incentives to promote that rather than ban Uber.
For all those downvoting ...what's the solution ? Go to phone call expensive taxis ? Uber is such a useful utility, most people won't let it go away. Too big to fail