I don't really understand the previous arc about the debt collector but I don't think it has any importance to the main story so I'm just going to ignore it
I’d like to believe the reason why the speedwagon foundation doesn’t help the joestars/stand users directly anymore in dangerous situations is because they’ve seen the casualty it has caused to them at part 3
They’ll help reach their goal but if it will harm and or cause the death of their talents? They’re out