Because they are? That’s why each state has a Governor and a Congress? Because the needs of the people in Wyoming are not the same as the needs of the people in California? We’re a Union of separate States under a Federal representative government; aka UNITED STATES (note the plural?). That’s why there’s two houses in the national Congress, and why Presidents compete for States, not popular vote alone. Because each state IS significantly different from the others and have their own unique problems, cultures, habits, and needs.
And while each person in Wyoming has more ‘voting power’, it’s because their state is only worth 3 Electoral votes. Without the Electoral System, the greater Midwest would be absolutely worthless to Presidential candidates. They wouldn’t need to care about the problems in Wyoming, Montana, Arkansas, Kansas, etc, leaving these states effectively voiceless in elections, their concerns unaddressed.
The system ensures that the states with the largest populations have the highest values, but the states with smaller populations still carry significant weight, compelling Presidents to actually at least give a show of caring about their problems and perspectives.
Welcome to a representative republic; where you can’t just do whatever you want simply because you have more people. The power and rights of the smaller states are protected by the Electoral College and other systems so that no State is voiceless in government.
So please, go to Texas and tell them they have the same problems as people in Maine. Or tell a man from Chicago that he might as well be from Brooklyn. Yes, we’re all Americans, but to pretend the States don’t have their own unique needs and cultures is just turning a blind eye to reality.