Philadelphia could follow the lead of other parts of Pennsylvania and implement a land value tax instead of wage and sales taxes. It's progressive, the most valuable land tends to be owned by the most well off. Renters already pay land rent, and this tax would capture a higher proportion of it instead of raising it since the supply of land is fixed.

If that step is too big, a switch to a split rate property tax that taxes buildings less than land would also help. This would benefit renters, since property tax on buildings does raise rents unlike the portion on land. It would lower property tax for many homeowners. It would help raise the supply of housing. https://whyy.org/articles/a-progressive-approach-to-taxing-land-gains-traction-in-philly-council/