On a macro level, evidence does strongly support that gentrification is a good thing. That doesn’t mean it doesn’t have downsides, including displacing low income residents in areas being gentrified. The fact this also creates huge reductions in crime is not coincidental though.

There’s a bit of a chicken and egg problem here nobody wants to wrestle with: 1. Poor people commit the vast majority of violent crime. 2. People with records of convictions of violent crime cannot get stable employment. 3. There is a measurable intelligence and emotional regulation gap at the average between violent criminals and productive members of society. 4. There is a measurable intelligence gap associated with income in our modern knowledge-based society. 5. Inability to get stable employment and low impulse control both are major contributing factors to recidivism.

It’s a heavily intractable problem, it’s clear retributive justice is not as effective as rehabilitative justice, but creating a feeling of duty of care in the communities harmed by crime is a nearly impossible ask. Gentrification at least provides a way out to improve communities for those residents who can afford to stay.

If that's what it sounds like, I'll hazard a guess that you never made it to the research.

If you have a neighborhood with abandoned buildings, some of which are burned out or boarded up or just have all the windows smashed out, and you then clean up the abandoned buildings, then property values will go up. When property values go up, rent goes up. Which part of what I said disagrees with 'the research'?