The primary change wrought by the 17th Amendment was to move the locus of corruption to K Street in Washington.
Wouldn't repeal of the 17th Amendment simply move the locus of corruption back to the states? Would 50 loci of corruption be an improvement over just one festering sore in DC? I'm merely posing the question, not proffering the answer.
An improvement ? In a word, no. The argument at the time is that it would be much harder to bribe the voters en masse of a given state than bribe a handful of legislators.
Term limits are more important. But after that is out of the way, congressional appointments on an ANNUAL basis would give voters a chance to shake the entire tree of politics rather than just at DC. And the state legislators would feel less impotent, more able to serve their constituents effectively. So the relationship would be rebuilt.
Combine that with modern communications, and it would be a vast improvement.
Lastly, voters would be less emotionally invested in appointed senators, eager to demand that the bum be kicked out at the slightest annoyance.