A problem with gentrification-led involuntary displacement is that it makes being poor even more unaffordable by pricing people out of areas where there's at least semi-decent public transit available.
In my urban hellhole there's a lot of talk of gentrification and displacement. I think it's somewhat overblown, which is not to say it doesn't happen at all, just that to a great degree if your apartment becomes unaffordable then if you move 5 blocks in some direction it's affordable. But if trends continue for several more years, poorer people might be forced out of transit rich neighborhoods. Cars are expensive.