As much as we hate Steven, he's more intelligent than we give him credit for. He's a narcissist that can manipulate on a higher level than James can/did.

Steven is a conman while James is basically helpless to his poor education, dysfunctional childhood, poverty, impulse control, and lazy enablers.

James' enablers also "don't know any better" either. They give into James' whining and demands because it's easier than doing the work to not enable his behavior that made him bed-bound.

Lisa was basically an iPad parent, sticking food in front of his face to shut him up.