The cooling effect on supply?? You mean Taylor Swift's inability to be in two places at once and unwillingness to drive her voice into the ground by continuing to add more concert dates?

No, this is not the right argument. She had to go with the biggest venues in the US to fit as many people as possible, and she's already added a ton of extra dates.

There is a fundamental limit to the number of people who can attend this tour, and that number is lower than the number of people who want to attend this tour, therefore prices will go up until the demand for tickets matches the supply of tickets.

Independent venues would not have made a lick of difference in this case, these ticket prices would be sky high no matter who was selling them.