This is basically what the OP is saying: it's not something specific to SBF or related to his political connections, but a more general issue in prosecuting white-collar crimes.
Although rerouting the massive amounts of money + human capital in non-violent crimes (drugs) to white collar would help... and probably pay for itself in recovered money (via tax revenue and reduced government corruption).
That probably still wouldn't result in SBF-type criminals being arrested right away though.
Occupying territory is expensive.
There’s far more waste in other federal agencies if you need to find one, NYPD is probably not a good one to point fingers at.
Raphael Bostic insider trading as president of the Atlanta Fed was practically a non-story.
Most people just don't care.