> In your opinion, what is the best approach, if any, to attempt to address it?
There aren't many options for fighting the tax man, "In this world nothing can be said to be certain, except death and taxes". You're only option is to leave the US for somewhere better.
Correct, the US is one of the few countries that tries to collect (Federal) income tax from all citizens regardless of the country they are currently living in. To be fair, when you can prove that income is entirely foreign (not a single US company in the chain of ownership) that income becomes almost entirely deductible and the tax reporting essentially just a census on how well US citizens are doing from an income standpoint globally. (For people that want economics analyses of US influence in global politics, that census can be handy to spin.)
I think the root problem with how the US currently spends its tax dollars is the above "vote with your wallet" belief in the first place. "Vote with your wallet" implies that the rich deserve more votes. That's not (representative) democracy, that is oligarchy. Right now the US has two political parties that are both "vote with your wallet parties". They both act like they are bake sales that constantly need everyone's $20 bills just to "survive", but as much as anything they are trying to make US citizens complicit in agreeing that the rich deserve more votes and should control more US policy.
I think the only real solution to a lot of US ills is drastic Campaign Finance Reform.
Minor correction, expat income is deductible up to (currently) $130k under the FEIE. After that it's taxes as usual. There's also an array of other mandatory forms like FBAR for foreign accounts, and the nightmare that is form 5471, with absolutely wild allowances for the IRS to impose penalties, often with no statute of limitations and per-violation fines. For example, a US citizen with multiple bank accounts and a mistake in FBAR reporting for multiple years running will be liable for the (iirc) $10,000 fine for each bank account, and each year (e.g. 4 accounts, 8 years, $320,000 fine).
Living and doing business overseas is as a US citizen is a high risk endeavor.
FEIE is only one of the options for avoiding federal income tax. The other is the Foreign Tax Credit, which has no such limit: https://www.irs.gov/pub/irs-pdf/f1116.pdf. If the place an American lives and works has a higher income tax rate than the US one, in practice he will not face any tax liability, regardless of income level.
Unfortunately, campaign finance reform would possibly require a constitutional amendment, or at the very least a big shift in how the supreme court views things (so, not likely in my lifetime), since the current jurisprudence is that limiting campaign donations is a violation of first amendment rights.
Yes, many countries have significant limits on campaign donations. Even third parties are restricted from advertising on behalf of a party, and so on.
So no company can simply donate large sums of money, nor can any single person.
The goal is that individuals will be the largest donors, not companies, and that as everyone is capped in the same way, advertising will be a more level playing field. We don't want money in politics. At the same time, we want all parties to get their message out there, their message heard.
It's not perfect. There are issues. But this business of democracy should be taken seriously.
The US technically even has laws that that were supposed to do that still on the books. A particular problem was a very broken decision by the US Supreme Court in Citizens United v. Federal Election Commission [1] that opened too large of a barn door that the US has been reeling from ever since. That trial argued that companies were individuals/people and that money was the "free speech" of companies and shouldn't ever be curtailed. So there are so many things wrong with that court case on so many levels. It led to the rise of Super PACs (Political Action Committees), companies designed to launder money for political gain where the donors are allowed to remain anonymous and the Super PAC "speak" for them, because now it was "free speech" and not bribes and regulatory capture.
I know pessimists that believe the only way the US succeeds in the Campaign Finance Reform it needs now is through a Constitutional Amendment and if we can't count on Congress to be interested in it (due to bribery), and not enough individual States seem to care (some because they want a chunk of that pie), it's going to take a full Constitutional Convention to pass that amendment, something that hasn't successfully been done in the US since 1787 (also, the first attempt).
There have been some fairly longstanding judicial decisions overturned recently, although I know the reasons are not in alignment with the decision you mention, it does mean there is hope for such change.
So maybe it's actually far less work than considered. Maybe, attacking the decision with a modern eye is helpful.
Citizens United was a 2010 decision. Several of the judges on that case are still sitting judges in the Supreme Court. Since then one of the Congressional oversight decisions on vetting replacements for Supreme Court judges has been whether or not they (at least claim to) agree with the Citizens United decision.
The decision was made in the modern eye, in my lifetime. (The country needed modern Campaign Finance Reform before that point as well, but that decision marks an inflection point from Campaign Finance Reform feeling possible through normal means and court decisions to nearly impossible to overturn in our lifetimes.)
For the ultra-wealthy, leaving the United States is rarely the preferred strategy; instead, they use their immense resources to legally reshape the tax code and utilize complex loopholes. Billionaires like the Koch and Scaife families historically avoided massive estate and gift taxes by creating "charitable lead trusts" and private foundations. This allowed them to pass fortunes down to their heirs tax-free, provided they donated the interest to charities (which they often controlled) for a set period. A powerful approach is to fund political movements to slash taxes for the top brackets. For example, a coalition of eighteen of the wealthiest US families spent nearly half a billion dollars collectively to successfully lobby for the reduction and eventual repeal of the "death tax" (estate tax), saving themselves an estimated $71 billion.
And, of course, in the ancient world, free citizens of Greece and Rome considered direct taxes tyrannical and usually avoided them, leaving such burdens to conquered populations.
So I guess taxes are uncertain, but only for the oligarchy.
There aren't many options for fighting the tax man, "In this world nothing can be said to be certain, except death and taxes". You're only option is to leave the US for somewhere better.