People move to Puerto Rico because unlike US States, as a US citizen in Puerto Rico you are exempt from federal income tax.
To move states you essentially just move and then register at the DMV. To move to PR, you have to properly live their 6 months out of the year.
People who do this don’t stick to it. Despite being a US territory, it is not convenient to get to. If Cuba was open to Americans, it would be way more convenient to go there. A flight to Miami is around $90–130. A flight to Puerto Rico is $250–300. It’s further away with less traffic. It is not a hub.
Non-islanders will end up bored. They don’t move for culture, they move for taxes. And a life oriented around tax minimization is about as invigorating to the soul as it sounds. It’s boring. You are lame if that’s all you want, and don’t deserve respect.
If you love Latin America, have friends or family there, or just want to chill out for a few years, this is a great idea.
Additionally, if you are on the cusp of the windfall of a lifetime (i.e. selling your company) it could absolutely behoove you to officially change your residency. live there 6+ months out of the year, and pass a bunch of other criteria. The details matter.
There are niche circumstances and people for whom this is the perfect idea. Would I recommend it to everyone? Absolutely not.
But if you are tired and need a break for a couple of years, want to sell your business, and you have people down there to spend time with, this is quite literally the perfect opportunity for you.
Hire someone to actually advise you on it.