I'd be interested in hearing more about the claims made at the beginning of the article and the sources of those.
I moved to SF in 2012 when uber was barely a thing (still only black cars) and haven't noticed the traffic being worst. I've also not noticed any parking spots that are now free (but even if this happened, isn't that a good sign?).
To the opposite, and again my own sources are biased since I worked at Uber for a while (i'm not anymore), but I've heard a lot of studies proving the opposite - reduced traffic, better for the environment, etc.
As an example, I googled "how many cars per day in SF" and the first thing I found is that 110 000 cars cross the golden gate bridge alone. I'd assume the Bay bridge is seeing at least that if not twice. So the argument that 5700 more cars because of Uber and Lyft in the city are the cause of traffic seems a little short sighted. It's also the same argument that was made by De Blasio a few years ago about NYC and studies proved that it was false.
I'm not saying the article is lying or anything, and again, I'm very biased, I'm just surprised to see an article from Engadget making such claims without links to sources/studies. The author saying "I'd realized congestion in San Francisco had gone insane" doesn't convince me this is particularly true...