And ignore the fact that Carapaz has beaten Roglic and only lost to him due to time bonuses in their last 2 grand tours where they were riding for GC. And ignoring the fact that Pog's TT was an absolute freak and nowhere near represents his normal performance level.
I don't know who ignores those facts, but I think the time bonuses thing is silly. Time bonuses are a big part of GTs and other stage races as well. It's an important rule. Similar to the rule when the last rider in a group gets credited with the same time as the first rider of that same group, despite there can be 3s, 5s, or 10s between them in real time on the road. Did you also count those occasions, when Roglič won the sprint of a big group, while Carapaz was chilling behind in the middle of the group, yet they both were credited with the same time? I remember a stage from that Vuelta, where Roglič badly outsprinted everybody on an uphill finish, yet because there was a touch of wheels 300m from the finish, everybody got same time as him. But those are the rules and you have to adapt to them. There's no special final ranking without time bonuses, like there's no special final ranking and jersey for the winner without TTs.
Also I'm not going too deep into the Giro 2019 because I could end up writing an essay. I'm just gonna say, there are many different circumstances with a lot of factors to consider. People also ignore the fact that Vingegaard beat Pogačar in Pais Vasco. Just to give an example.
Having said that, I absolutely expect Carapaz to be strong and he'll be a serious threat to win the Tour.