The people who wrote the constitution had plenty of experience with the First and Second Continental Congresses, and the Congress set up by the Articles of Confederation. And Parliament, and state legislatures. They both loved and feared democracy. Not everything in the constitution is meant to be democratic.

Senators were originally appointed by state governments to prevent the federal government from slowly weakening the states ( https://constitution.congress.gov/browse/essay/artI-S1-2-3/A... “To further allay Anti-Federalist concerns regarding concentrated federal power in Congress, the Federalists emphasized that bicameralism, which lodged legislative power directly in the state governments through equal representation in the Senate, would serve to restrain, separate, and check federal power”). That’s not really “democratic.”

In grade school, we focused on the fact that states with small populations weren’t enthusiastic about letting larger states set national policy. Sure, New York would have been happy to have more influence in both the House and the Senate than any other state, but Rhode Island, Delaware, and Connecticut weren’t going to sign under those terms. Horse trading to get them to join wasn’t “democratic” either, but they wouldn’t have joined any other way.