Don’t disagree with how the Founders would have felt about popular election of senators.
However, limited experience with state legislatures in three states makes me think they are if anything even more venal and corrupt than the Congress.
OTOH, I don’t have any real first-hand experience with Congress. :)
The Framers looked at them this way. Self-serving politicians were as certain as sunrise tomorrow. Freedom is secured by dividing power, so if state politicians did what they were expected to do, they would protect their turf. By being themselves, even corrupt, they would keep the new federal government out of state concerns.
It worked.