Anytime you score almost 15ppg and make it to the title game is going to be an accomplishment. But when you said he was "elite offensively" in the NCAAT, I expected it to be a bigger jump from his season averages. Especially when he shot worse from 3 and FT, and cut his assists in half.
Yes, competition was better in some regards in the NCAAT. His best NCAAT game was 20 and 11 against Montana, who was final KenPom #72. I thought his game against LSU (28 and 8) was more impressive, and even though they didn't make the NCAAT - they were still ranked higher (KenPom #66) than Montana.
Looking at his stats against NCAAT bound teams during the regular season, he was under his season averages in most of those games (UNC, OSU 2x, Texas, Purdue 3x, etc).
So he definitely stepped up when needed (NCAAT). Which is what you need to go deep in the tournament.