Philly is corrupt. The main line is autonomous (as are all townships in PA) in how they assess and administer prop taxes. Before the 2000 assessment, homeowners paid about 40% less. So, the building of schools and paying of teachers was all done with far less than in recent years revenues.
As far as RSF and RB, was there ever a time when RSF was ever representative of the average tax base? Even 20 years ago, was it really reasonable in price? All I know is that was where Joan Crock and Gene Klein lived. It is about as old as money gets here.
The beauty of prop 13 is new assessments occur with each transaction. While I am sure there are the examples of those homeowners who have lived in their homes for a generation, intuitively I would assume with all the building over the past 20 years and all the home sales in that same period, a wealth of tax revenue has been gained.