
..The US is one of the few countries that taxes its citizens on foreign earnings...meaning if you owned factories in china you owe the IRS even if you live in china and hadnt lived in the US all year
So for many rich people who live overseas with profitable foreign holdings figure its cheaper and better to renounce than handing over 1/3 of what you made to the IRS to pay for shyt youre not even there to use
And IF you dont pay what they figure you owe they can freeze your bank accounts and get your assets seized and have you arrested and extradited to face a prison sentence..and your host countrys lawyers cannot fight the extradition because you are a US citizen wanted by the US govt

one day youre living the good expatriate life sunshine, beaches and bytches ...the next youre someones bytch in some federal prison in ketucky