That depends on how taxes are collected. It might be true or not depending on the city. As an example of why it can be bad, argentina has subway in Buenos Aire

That depends on how taxes are collected. It might be true or not depending on the city. As an example of why it can be bad, argentina has subway in Buenos Aires, and it used to be federally owned. That meant taxes from all the country paid for subway in the city. OTOH if you have income taxes (i think they do), as a renter, you will pay a tax that goes to build a subway that makes the rent where you live higher. My concerns of free public transportation would be that it would encourage very strange discentives. For example, a postmates company can say that all deliveries are done on public transport, which means basically the state will be subsidizing some kinds of businesses, to the detriment of others (whole sale retailers for example). Also free transport will make people extend their commutes, because now a very long trip doesnt matter if its costly. This happens in argentina.