Among Nepo’s achievements are a bunch of tournament wins, for example Dortmund, Tal Memorial, a couple of Russian Superfinals, of course the Candidates, etc. Maybe not an outstanding list compared to some of his contemporaries. And even if for example Kramnik never won the Candidates or Russian Superfinal, he had a long list of top tournament wins at 30.
Nepo does have very impressive head to head stats against World Champions. His 4-1 in wins against Carlsen has been mentioned rather often, even if some of the wins are far back in time. However, he is also 5-4 against Kramnik and 3-2 against Anand. He never played Kasparov and Karpov in classical, but has a plus score against both in rapid. Which maybe is less surprising, against Carlsen, Kramnik and Anand he was the lower rated player.
Nepo also has a plus score against Caruana, after winning the only decisive game they played since their first against each other in 2006.
Most greatest ever lists are topped by the (”real”) World Champions plus Morphy. The one made by GMs Nielsen and Gustafsson at Chess24 is no exception. Now what if Nepo beats Carlsen, where would you rank him among the greatest? Or, if he loses? They placed for example Nimzo, Karjakin, Winawer and Leko in the 40s, but Shirov and Short outside the top 50. Where does Nepo belong, and why?