I'm not saying that you're wrong, but the flip side of that argument is that whenever you do see higher investment and better amenities in a historically marginalized neighborhood, that gets loudly deplored by faux-progressive activists as harmful "gentrification" and "changing the character" of the neighborhood. Y'all should pick one stance or the other; you can't have it both ways!
You're attributing views to me I do not hold.
And frankly, you characterization of those views makes clear you're not interested in actual answers.
The primary issue with gentrification in historically black neighborhoods is that owners face the dilemma of having to leave their community to capture the increased property values.
For example, I live near the oldest black church in the PNW. Many of the older congregation members live in the area, and have low mobility. If we don't build a mix of housing that addresses their needs in downsizing, they end up having to effectively exile themselves from the community they've lived within for decades. They can't simply "move somewhere lower cost" without dramatic changes to their entire social world, just at an age where keeping those social ties takes a lot of effort.
So the thing about "Ya'll should ..." is that it's often mistaking "Group A and Group B hold conflicting beliefs but share a characteristic" with "Group C, all the people with this characteristic, all exhibit an incoherent belief structure".
For example suppose you apply this to the US Senate. So instead of Group A (Democrats and a those who caucus with them) and Group B (Republicans) we instead think there's a single Group C, Senators. Now their behaviour seems incoherent, this Group C seems to hold contradictory opinions and behaves irrationally, why can't they get their act together? The actual answer is that we misunderstood and they're not a single coherent group so that's why they don't act that way.