In that particular case the hold arguably stopped a touchdown pass, even if it wasn't that flagrant. It was a timing pattern where the receiver runs under it. The receiver was unable to get there because of it. If the hold had been somewhere that Mahomes wasn't looking the call would have been a bit of a travesty. But JuJu Smith-Schuster appears to have been the primary receiver.
The Chiefs wanted a first down, not a touchdown, because of the hold, the receiver wasn’t open, and Mahomes threw the ball away.