If you consider citizenship to be "no benefit" (you can still vote, collect Social Security, etc. overseas), you could always renounce your citizenship.
And as for voting, why? I have no representative to vote for.
https://travel.state.gov/content/passports/en/abroad/legal-m...
If you honestly see no benefit of your US citizenship, or the costs outweigh the benefits, it sounds like you should change your citizenship status, perhaps to the country you're a resident in, or maybe move back to the US.
Social Security is not a savings plan no matter how much you would like to think it is.