Logically what you’re saying makes sense, but we’re only single-digit generations removed from the founding of the country in which state identity was much more important than a United States identity. Even today the cultures of people in states are noticeably very different and many people still identify more with their state than with the country as a whole. So what happens when you say to them, sorry your state is no longer able to decide anything about this union of states because your votes will be completely dwarfed by California and Texas? Obviously that’s going to upset tons of people, and if you were a small state you’d want to pull out if you were federally taxed with functionally no representation.