And what about what we would call "contract work"...
It's called Monotributista. There is a limit up to what you can earn per year via this method, and you actually pay less taxes. But you have to do a bit more paperwork than in the US and it's probably best to let an accountant handle that part, which costs against what you save in taxes.
Not many Argentinos want to work like that because it's complicated and there is some issue with relinquishing your status as Monotributista if you go to work for someone else later.
As in everything LatAm, particularly here, everything is complicated and difficult. Watch the US become more and more like this as everyone tries to make things more "Fair". The US is already on that road...