The 17th caused Senators to be more beholden to D.C. and less responsive to the individual states. It also ushered in a SCOTUS less inclined to consider States Rights because they are now confirmed by a more “federal” Senate. On the flip side there was so much corruption in State Legislator’s that the the integrity of the Senate was compromised. See Illinois 2008.
It was a 3 legged stool POTUS, States, People. The 17th kicked one leg out. States and People were supposed to make up the Congress. States = Senate People = House electoral college =POTUS. The formula which retained the Republic is on the cutting floor leaving the Feds to amass unlimited power.