Not sure about "most." Even in smaller cities free street parking is getting pretty rare. My town charges $1/hr for meters and it's clearly too cheap because it's still hard to find a spot most times.

Certainly in urban centers like downtown Chicago there is no such thing as free parking, even at hotels and office buildings.

Merchants decide where to locate in part based on traffic counts (vehicle and pedestrian). Places that are more valuable to merchants are more valuable to the city (property taxes and sales taxes are higher).

It's economically logical for the city to consider whether to offer this investment/subsidy.

Edit: I should put this in context:

The merchants felt the city (which collects sales tax revenue) would benefit by subsidizing parking, which allows for more traffic and theoretically leads to increased sales (more tax dollars). The city saw parking tickets as a greater source of revenue, and felt increasing enforcement was the better plan. The merchants paid meter-feeders selectively, so as to encourage locals who are a more consistent source of revenue.