Does Uber exists?
Unless it has popped back again without me noticing, I don't believe there is. It was in the city for a brief time a couple of years ago but there was so much opposition to it locally that what with that and licensing issues, they suspended the service. It's very difficult to obtain a taxi driver's license in this country. Regular taxis are plentiful so it's no big deal.
I've never had to wait more than a couple of minutes for a taxi - there's no need for Uber.
"Regular taxis are plentiful" - and not outrageously expensive , unlike somewhere like Amsterdam, where taxis are horrendously expensive and Uber is very popular,
We just took a taxi from Schiphol to our hotel in Amsterdam.
We got to ride in a huge, amazingly comfortable, gull-winged Tesla that went like a bat out of hell. The happy driver told us it would do at least 260 kph. I checked later and saw that the damned thing retails in the Netherlands for something over 150,000 euros.
It was worth a few euros extra.
The only place in Italy where you can find Uber is in Rome and Milan it works brilliantly as the drivers are al NCC - noleggio con conducente as Marco mentioned above in Italy by law to take passengers you must have this type of license
In Florence you can find taxi stands all over the city centre and if you are in a restaurant, Hotel you can ask someone to call a cab for you