Thing is, in most cities desegregation usually means gentrification, which certainly reduces urban crime, poverty and blight, but also displaces the lower income people who called these neighborhoods home.

Good point and worth bringing up. I'd like to elaborate on this issue.

"Fifty Shades of America" did an episode about this topic that was pretty good. The direct issues pointed out were the rise in housing prices, the replacement of basic staple businesses and services with niche services, and replacement of housing altogether with commercial buildings. In other words, the houses that existed got more expensive, laundromats and food stores got replaced with kambucha shops, and land developers bought and knocked down housing to create commercial office space or additional retail space. The housing got more expensive and more limited.

Integration is possible, but it requires careful community planning, guarantees of low income housing, walkable neighborhoods, conveniently placed and appropriately funded schools, parks, community centers, rent control for existing residents, and other things that don't immediately come to mind. Even ignoring the segregation, we have poor community planning in general. The rise of suburbia and the automobile as well as zoning laws played a significant role in putting jobs and essential businesses like grocery stores far away from affordable housing.

It's a mess, but it is one that can be fixed, though it's an issue that ultimately has to be handled at a local level. We can create federal incentives but this is something that states, counties, and municipalities control. Much like the expansion of medicaid, if the local government doesn't want to do it, we can't force it on a nation-wide level.

I've never seen rent control implemented fairly. It tends to result in low rents for a privileged few (usually boomers), and extra high rents for everyone else (especially millennials).

Metroplanning website, with more detail and the actual study to download.