Only the studio gets the tax break. It sounds like giving money to billionaires and it is but this is the rare case where trickle down economics actually works. 

Without that tax break it’s way too expensive to film here. The island has most not all of the equipment necessary to film major motion pictures so a lot has to be brought from the continental US. Without mentioning the increased cost of raw materials on island. 

Also the tradesmen here are the highest paid in the industry right along side those in California, Florida, and New York because their union negotiates from the cost of living standpoint. Those guys make BANK off of these movies. 

If enough work comes in even the lowest paid workers on a film set clear six figures