The competition isn't the best there could be, that would be with Roglic and Lopez in top form in my opinion, but it's not weak, I find that slightly insulting.
First of all Pogacar won the time trial ahead of Küng, how is that because the competition is weak? It's easy to say "oh, from the maybe-contenders Vingegaard was second", forgetting that he also put some decent time into other guys like Asgreen, about a minute into Porte and Uran, who aren't weak time trialers.
Second Carapaz, who climbing wise I would consider slightly below Roglic, but not much, tried to follow him on the way to Tignes, and was completely unable to. Also if I remember right Jumbo have said Roglic could not have followed him there.
Thirdly, Vingegaard, Mas, Gaudu, O'Connor, Kelderman etc. may not sound like the best of the best, but the preparation races and the early season showed that they are roughly about the level of Geraint Thomas if all healthy and fit. No way could Thomas, had he not crashed, taken it to Pogacar in any way. The only one who could have been closer to Pogacar had he not suffered from crashes and the cold was Lopez, who would always lose a good deal of time in a time trial.
The other top 10 contenders aren't weak. (Mostly they are young and haven't had a stellar first years, many riders don't.) And he gained about three minutes thirty on them on one climb; I know that they didn't really try to catch him afterwards anymore, but neither do I think he really went all out, he was certainly pushing hard, but he never looked (and I don't mean his facial expressions, I mean his movements) totally in the red, he was on his own, and he eased significantly on the way down.
Basically, he's just extremely strong. No need to say the competition is weak.