Add 60km of TT and the same 12 guys would be in the top 12
The 2 best / most consistent climbers are also the 2 best time trialists.
Pogacar the best climber and best TTer of the GC guys
Vingegaard 2nd in both categories
And that's with Roglic crashing out.
on a more ITT-heavy route Uran (usually not a great TTer) could beat Carapaz for 3rd place , but that's about it.
Bernal is not a better climber than Pogacar, Vingegaard and Roglic IMO, except maybe at altitude. I don't think it would change much, although I get the usual argument that it could lead to more aggressive racing in the mountains. But with the current crop of GC specialists... I dunno.