I'd love to see either state or federal buyback programs. Using the same appraisal rates used to calculate a property value when setting property taxes most states could offer to buyback properties at 80% of their assessed market value and then have redevelopment programs to reinvigorate dying neighborhoods like in the OP.
It lets the poor escape dying neighborhoods much easier, and it also creates a pathway to save these dying cities for relatively low investment by creating job opportunities to fix the state possessed properties or put them to auction so they can be competitively worth fixing. Either way the state should not be out the money for very long - you have a depressed area that has terribly low property values because its an impoverished slum, let the residents sell the land off as a means to get out of that hell, and then make a deal with a redevelopment firm or use the civil engineers corps and then sell the resulting revitalized properties, hopefully after some mixed used development.
That last point is probably the strongest reason why the US in particular has these widespreading "dying neighborhood" problems. Zoning for the most part has been an abject failure. It was conceived to segregate the rich from the poor and has failed to recognize that a thriving community needs work and play to intermix and develop organically. It also exists to constrain development to prevent cities from growing up and increasing density to meet population demands, all to prop up the real estate investment bubble making the semi-rich filthy rich.
Spending public funds on these endeavors ends up being something of a middle class bailout. Are folks who were fortunate enough to be able to purchase homes in the first place. 70% of those in the bottom 20% of the income distribution do not own their homes.