What this article misses is Nepo is famous in the chess community for caving into pressure after losing once. A lot of people have said that Nepo was immensely lucky with the Candidates Tournament (the tournament that allowed him to play for the World Championship) since that tournament was split into two parts due to COVID. The break happened precisely after Nepo lost a crucial game and allowed him some time to regain his composure. I doubt Nepo would have won the Candidates if he had to play immediately after his loss.
On the other hand, Carlsen is well-known for his mental fortitude. It’s something that Vishy Anand, the previous champion, has talked about extensively. Carlsen’s style is often called “squeezing blood from a stone” because he will play equal-looking endgames and mentally exhaust his opponent into making a tiny mistake that he will convert into an advantage.
It was indeed a tough match-up for Nepo, and most knew it would end tragically for Nepo. Despite being an excellent player, he’s not on the same level as Carlsen.