I think the reason wasn't section 936. The reason was more the local government not putting to good use any of the benefits from either the bonds or local companies setting up.

Instead of using those funds to improve education, technical training, create buildings/projects that made sense in the distant future where funds/companies would not be so incentivized to stay here. They went and started building pointless infrastructure projects with arguably benefits or ROI almost always with some sort of controversy on the project builder/developer intentions.

Building statues, pointless sports venues, really expensive projects with zero to marginal benefits to society/Puerto Rico's economy long term.

Agree that they were not the most prudent financial managers, my point was as soon as they changed the tax code; there was a 10 year window to sunset it and almost all of the companies left which really decimated the economy where jobs just vanished as they were moved back onshore and satellite offices closed.

You're right, many companies left after they 936 decrees expired, but they weren't cancelled right away when the Congress changed the tax code and got rid of section 936. Same with Act 20 and 22, once they are signed, you're good to go for 20 years, even if the laws change in the future.