It’s very hard to let go of the past.
And that applies to national polity too.
The Senate as construed originally in the US Constitution was intentionally anti-democratic. It was created to perpetuate the power structure of the colonies.
It is obsolete and each year into the 21st century shows that more and more.
Sure, having a senior body to do oversight is fine and all political structures need that. But that does not mean such a body should be involved in legislating laws or allocating revenues or voting on political appointees.
But Americans are very religious, and transfer their religious feelings of reverence (mostly to the Bible for fundamentalist Protestants, or to historical institutions for other theists) to the US Constitution, as if it is somehow inerrant and unchangeable.
But it was designed to be change.
And it needs some radical updating.