This guarantee was the price of having all 13 original states agree to a Constitution in the first place. So we’re stuck with the theoretical possibility that Senators representing 51 states with 18 percent of the population could cast a majority vote.
This doesn’t matter much with enactment of laws. For a bill to become a law, it must also be approved by the House of Representatives, which is chosen on a population basis, then signed into law by the President or passed over his veto by a super-majority. But to appoint judges, ambassadors and other federal officers, the President only needs the advice and consent of the Senate.
Most democratic nations have parliamentary forms of government, in which the parliamentary majority chooses the Prime Minister and routinely approves the PM’s proposed laws and appointments. If the executive and the legislature disagree on any important measure, the people get to vote on who is right.
These systems work well most of the time. When they don’t work, it isn’t because of the tyranny of a majority, but because there are multiple parties than can’t work together. I don’t think the people of any democratic country would want to create the equivalent of the U.S. Senate.
We Americans don’t have a choice because the principle of state sovereignty is baked into our Constitution. I think there is a case to be made for our exceptional system of checks and balances, but I don’t think we need to carry it beyond what our Constitution requires.