Yeah, I think they are just pointing in the line of succession doesn't do much if the VP was chosen by the president. We only made it 4 electiona before the 12th amendment was made and killed any hopes that the line of succession would be useful and Washingtons hopes that we wouldn't become a 2 party system were completely dashed.

Without the 12th Amendment I have no idea who would be president right now. Biden would have never been Vice President and such likely would have never been President. Harris the same. But the President would likely have an obstacle at all times in the Senate as the only way to get both the President and Vice President elected for the same "party" they would have to have 2 candidates beat 1 of another party, splitting the vote of their own party. In today's media age, it would be really hard to have gotten that done.