Truthfully, why should one be a citizen? It seems like you get all of the benefits of citizenship, plus the benefits of being a non-citizen, by being a non-citizen.
Given the current geopolitical landscape, citizenship brings a lot of perks these days and that is only accelerating. Also the fix for the issues of people being taxed without representation is immigration reform to make it easier for people to legally immigrate, not allowing non-citizens to vote. Whether by hook or by crook, we'll have to reform our immigration policies eventually because the declining birth rates of the West make it imperative if we want to maintain a world-leading economy.
Um, being an immigrated legal permanent resident does not give you any representation. The problem of taxation without representation is not that immigration is hard, it's that you are taxed, and you have no representation.
You can be a temporary (think H1s, student visas, etc) resident, a provisional permanent resident (essentially it's what lets you be a resident for the extended period it takes to approve a green card in which your original work permit might expire), or a permanent resident (i.e. a green card), and in all those cases you pay at minimum the same taxes as citizens.
What perks does citizenship bring? You have to do all the paperwork if you want to go anywhere, you have to follow all the rules, and you still have to pay taxes even if you leave the country. Being a citizen or even a legal resident is just a bad deal at this point.
On the other hand, if you just walk across the border, you qualify for all of the benefits, and even now get to vote just like citizens, but there are no obligations at all. You even qualify for free housing, free healthcare, free internet and cellphone service, and free food, just for showing up without papers.
Non-citizens pay at least the same taxes as citizens, I recall there being some write offs that were only applicable to citizens so it's possible that non-citizens pay more in some cases.
Obviously non-citizens also pay the same sales taxes as citizens.
The only difference is you don't get a say in how your tax dollars are used. So much for "no taxation without representation".
Oh, and have to budget time for "random" delays at airports.
Immigrants in the US (including people who aren’t permanent residents) are considered residents for tax purposes and pay the same tax rate as citizens.
I'm pretty sure that Takoma Park, a close-in suburb of DC, has this already. Whether noncitizens not working for e.g. the IMF can afford to live in Takoma Park might be another question.
Citizenship comes with only drawbacks these days.