So all someone needs to drive in Sweden is this Taxi Driver license? Then they can just jump in their car and start earning?

Yes. It's a driver job like any other (bus license for bus, taxi license for taxi, truck license for trucks...). Most companies probably have cars unused at times. E.g. if you are a student and want to make some extra money it's usually easy to get a weekend job using someone elses car when that driver is off anyway. That way you can make some money without a big investment in a car.

so you can't just drive your own car? That's exactly what Uber is about.

You can use any car as a taxi, but to use for commercial driving your car needs to be just that - a taxi. So you’d spend say $1-2k to register it as a taxi (new license plates, install a meter).

So there are hundreds of taxi companies and Uber is just one and like all the others. Uber cars are registered with the vehicle authority as taxis and have regular meters.

So I just checked this out and you are a bitoff Here is what Uber lists as requirements: https://www.uber.com/en-SE/drive/requirements/

Meaning that you can either:

1. Get taxi driver license and driver for a fleet for a certain % to take home. This basically means that Uber is just one of the systems you use to get customers.

2. Get a taxi driver license, a sole trader company (1 person company) and a taxi operating license. This means you are a contractor for Uber, and pay the 25% comission. --> You do not need a meter --> You do need a specific insurance for taxi business.

So basically if Uber runs a fleet of contractors, it's massively more important than having taxi companies that operate phone-based (as well as app-based) ordering systems. They have massively more overhead than the tiny operations office that Uber needs to operate in any certain city.