I don’t see very much difference between the mafia and the corporations. Corporations are definitely less overtly violent. You act as though the mafia kept rents in check where they were operating. Please, do a study and see if gentrification has ever been slower in mafia controlled areas than other areas. All of the things you mention are easily researchable with a minor amount of effort that entails going to these areas and checking local records at city hall and local libraries. Yes, it would take you some time, but you would get an actual answer.

What I believe you would find is, no, the mafia wasn’t any better than the corporations. People are less likely to get fingers or knees broken today, but probably more likely to lose their whole livelihood. I think you would be hard pressed to find someone who had been affected by the mafia who would then turn around and say “we had it so much better back then when the mafia was running things. These banks just suck at this stuff”.