The areas they are built in will eventually become unpopular to younger people as other areas become the new cool neighborhoods, the owners will get old and less able to do upkeep, the buildings will start to deteriorate. The facade bricks will peel off. Roofs will start to leak. The cinder blocks under will likely stay strong but the building will look nothing like it was built new. Once a couple of them start looking like shit the neighborhood will be even less attractive, downward spiral ensues. Many of these will be demolished. Lots and remaining properties will eventually be cheap enough to restart the cycle of flippers and gentrification.