There are knock on effects such as dimmer prospects for those left than in the more integrated communities that proceeded as investment flees. People rightfully don't want to invest in areas deemed unsafe, where those investments would be at risk.
To be clear, where such barriers manifest in ways where people are judged or treated differently based on immutable characteristics or group identity instead of their individual character, this is wrong.
This is a pretty good take on the ramifications of race riots: https://www.pbs.org/newshour/economy/racism-riots-economics-...