Your bias is causing you to come to some faulty conclusions. I did not quote the number of medallions given out by the city (which by the way is around 7000 [0]). I specifically stated the number of people employed as taxi drivers, which as of Dec 2016, is 9500. [1]
> Most drivers can switch to Uber/Lyft if they have or want to buy their own cars, or get other jobs.
Although some of them can probably use their primary car for Uber/Lyft, many of them will have to take out a loan/increase their debt to get a car they can use for ride-hailing. Perhaps you aren't aware, but losses in sub-prime auto loans have reached their highest levels since the 2008 financial crisis. Given that taxi drivers make on avg about $35,000, it's safe to assume that many only qualify for subprime and will add to this problem. And this is happening all across the country.
To your other point, get another job: Doubtlessly some people will be able to retrain. Just as surely, a number of people will not be able to adapt. Being a driver is about as low skilled as labor gets, so there are hardly any where their previous experience can transfer. So what jobs? Retail
> Driving a cab wasn't lucrative, the owners of the medallions were the ones reaping the monopoly profits.
The best part of the shattering of these monopolies was the lesson it gives others investing in government shielded businesses.
I don't really care about the superiority of dynamic startups vs government shielded monopolies and honestly I think the financialization/commodification of parts of the economy such that people make bets on things instead of contributing productive value is not a good thing. But I digress, I'm more concerned with the shattered pieces left over in the creative destruction. 9500 formerly employed people with little future job prospects. That is .2% of working adults. It's not a huge amount, but it's not a drop in the bucket, especiallly when the city is again raising taxes and these individuals are going to need government assistance.
As us in the tech industry innovate and move forward, we aren't following the patterns of the past. When software eats industries, it destroys jobs a magnitude more than it creates. Let's be clear, coal isn't coming back and neither is manufacturing (BTW, the US is still the world's 2nd largest manufacturer and the leading advanced manufacturer, a fact that goes unnoticed) I personally don't find meaning or validation in life by having a job, but many do and UBI is a stopgap at best, but we really don't have any other solution at this point. That's what scares me....and people making rhetorical, ideological rants with no regards for facts.
[0] https://en.wikipedia.org/wiki/Taxicabs_of_the_United_States#...
[1] http://www.chicagotribune.com/news/ct-chicago-taxi-driver-de...