Jane Jacobs, one of the historical thought leaders behind modern urban planning, discusses in her book (The Life and Death of American Cities) how thriving neighborhoods have a mix of cheap old real estate and expensive new real estate. The old real-estate allows for places like dive bars, and general affordable housing to exist, where new buildings house chain stores, high end boutiques, and allow the neighborhood to grow to match current demand from new residents.
The key issue here is that this cycle works best in the long term, but can cause pain in the short term. Additionally, if the new housing doesn't match the complete incoming demand for the neighborhood, the prices of the old units rise as well furthering displacement. In turn, she advocated for the removal of zoning, for as it stands right now, there is an extreme demand for housing in neighborhoods that are zoned in such a way that restricts their density from matching the demand in addition to pushing commercial activity to fixed locations where prices will always be high due to demand to living within walking distances to stores.
The key issue here is that this cycle works best in the long term, but can cause pain in the short term. Additionally, if the new housing doesn't match the complete incoming demand for the neighborhood, the prices of the old units rise as well furthering displacement. In turn, she advocated for the removal of zoning, for as it stands right now, there is an extreme demand for housing in neighborhoods that are zoned in such a way that restricts their density from matching the demand in addition to pushing commercial activity to fixed locations where prices will always be high due to demand to living within walking distances to stores.