Puerto Rico now has rich consumers who pay the salaries of poor Puerto Ricans. Who then pay income tax.

Small slice from a big pie is better than big slice from non-existent pie.

Trickle down economics was long ago shown to be a complete fraud.

You're right. Money doesn't flow too easily from the most rich to the most poor without government intervention.

But state finance is separate issue from that. And money flowing to the most poor would not do much to state finance, because the most poor typically are unemployed and hardly pay any taxes.

If they taxed them, it wouldn't be a tax haven.