Remember how Roglic' win in the Vuelta never being in doubt was the only negative point about the Vuelta?
Decrease in ITTage is the counter to mountain trains and closer mountain stages, like slower tennis courts are the counter to changes in racket technology.
Now obviously I'm not saying every GT should have one 25km ITT, but I just think the days of 100+ km of ITT in a GT should be over unless something also drastically changes about mountain stages.
I think the bottom line should be about 40km of ITTage and I also think only the Giro could put in 80km of ITTs and still remain balanced.
Obviously all this would always depend on which riders are the best in the world at any given point.
Or closer mountain stages are a result of decreased ITT kms. Thing with Roglic is that he was probably the best climber in the race, so in that case the route doesn't really matter.
Get a Casero v Heras or Nozal v Heras again and it's different story.