With respect, I don’t think you are getting it.
Maybe things have changed, but I became a landed immigrant in Canada without the necessity to renounce my US citizenship and paid no exit fees. For a time the US tried to tax my Canadian income, but Congress made it such that I would only be liable for tax on income that would have been taxed in the US but was not in Canada. I had no such income.
I totally get it. This is why half of Florida filled up with South Americans in a decade. Educated people are the first to leave while they can.