Magnus was just being honest man. You seem to succumb to a common thinking fallacy that people who express criticism or negative opinions about something or someone must be jealous, conceited or just negative people in general. Meanwhile he was just expressing what is obvious to any strong player: Ding's level of play was subpar coming to the match, a league below elite at least. His play during the match was way below his peak level as well. Ding made 3 amateur player level blunders (hanging a bishop, missing basic tactics and missing transposition to a basic lost pawn endgame) in this match. Carlsen himself made 0 of those during 5 matches. Among his opponents Anand made 0 blunders of this caliber, Karjakin made 0, Caruana made 0 and Nepo made 2 (or 3 if you count the last game in which he was already playing for nothing as the match was decided)
Gukesh underperformed massively in comparison to his recent level (at the Candidates and the Olympiad). I am guessing due to nerves. That made the match closer than it should be. At the end of the day much better player won but it was way closer than it would normally be.