Sorry, maybe I wasn't clear, I don't ever use the services they provide and I won't because they are provided by the other country I am a national of. I have no links to the US. Zero.

I guess to fit in your analogy I live underwater?

What if you live in another town and are paying for that fire department? Just kidding. But really if you live in a country which has a tax treaties with the US, you also can offset your taxes with taxes paid to a foreign country anyway, so even for high-earners nothing goes to the embassy. If you do use the embassy, you generally do pay them fees of course.

The embassy is for maintaining relations with foreign countries, not just passports and birth certificates (and pricey notary services). That seems like a sideshow. When it comes to services for the public, they appear to spend most of their time dealing with visa applicants, based on the crowds and lines I've seen. They also do offer assistance for missing persons abroad; if you have a relative that goes missing abroad the embassy will investigate. That seems nice of them. I assume other developed countries' embassies are basically the same though.

Most people use their country's embassy approximately never.

Where they do need to use it (such as registering a birth) it's usually replacing use of a different government office, had they not lived abroad.

The US has an interest in maintaining embassies and consulates independent of its expat population. And we often pay for whatever services we get there, so you aren’t subsidizing us.

Additionally a government should think about practicality and fairness before it implements policy. It is impractical and excessively burdensome to try and tax residents of countries that aren’t the US. Despite your stated beliefs elsewhere, it does not take very much income or bizarre situations to wander into dicey tax situations that are frightening for the expat. A small business (which is taxable in the US if you net more than about $430) can mean difficult filing in the US. I don’t earn all that much, and I’ve spent a lot of this summer working on my US taxes for no purpose other than to have them piled up somewhere, unless some IRS agent decides to make my life much more difficult.