My frustration with the ever growing list of documents I have to fill out and new designations we have to understand and check (particularly after Trump’s 2017 tax law) as a US citizen with an LLC living abroad continues to grow. I never owe any tax because where I live and where my company is founded (Austria) I’m always paying more tax than I would in the US — but compliance is time-consuming and expensive. So I looked into this issue in detail, but decided against it for personal reasons. I’m quite sure (without going to look up the documents again), that it is your wealth, not your “gains” — which in this case is the same. Everyone’s wealth starts at 0, so everything you own is a gain above 0.
Looking globally is a great long term strategy, but it is not where we are now. The only way to get there is to make the current situation more costly than that. The only way to do that is to tax highly and enforce rigorously those people who give up their US citizenship but still live in the US and/or get the vast majority of their income from revenue in the US. It is really not difficult to implement. The problem is US government corruption.