“Yes, that would best be accomplished by repeal of the Seventeenth (direct election of senators), not by a wholesale rewrite.”
Yes, but how do you get that to happen without going through the congress (the senate would never vote on it and it would fail). The answer is a convention to propose amendments to the states.
And proposals have been put forward. Have you read Mark Levin’s book?
The first two words in Article V are, “The Congress” which is empowered, either to propose amendments, or call a convention upon demand by the states. There is no getting around congressional involvement, and they have resources available to bewilder (think; an army of lawyers, and money flowing in a torrent). If a convention is called, Congress will have its way.
“Mark Levin’s book?”
No, I haven't read it, but did see the interview on C-SPAN’s Book TV two or three weeks ago; a very good man. Have you read “Homage to Catalonia” by George Orwell? As a younger man, he went off to “fight against fascism” in the Spanish Civil War. If you'd like a view of hardball politics (meaning brutal and dangerous), check it out.