It was designed to have a bicameral legislature. The lower house was supposed to be full of your neighbors, folks that lived down the street. They were supposed to only serve for a couple of years at a time. It wasn't a lifetime job. One of their main responsibilities was handling money.
The upper house was specifically designed to be a bunch of old, privileged, party hacks from the states. They work six years at a time, and might stay in for a long haul. They are the architects. They are responsible for monitoring and maintaining the structure of the system and keeping an eye on the other two branches.
This is not where we are. Somehow we thought that the more democratic the legislature, the better. That is not the case. The structure of the system suffers. Somehow we have Representatives that have jobs for life. The system suffers.
Now I can't tell the difference between my senators and my representatives. They're all camera hungry partisan hacks voting solidly as a block. Voting for them is pointless.
It's not rich people. It's not privileged people. It dumbasses over the years that have hacked the system into something it was never supposed to be. Democracy is not some special thing where the more you get of it the better you are. It doesn't work like that. It never worked like that. You take apart the body of legislators that were specifically responsible to monitor and fix the system and turn them into run-of-the-mill politicians? Then the rest of it is going to fall apart. What else would you expect?