To be fair, Sam was playing with a bad rib injury last season. It was downplayed by everyone in public, but we know that injury was an issue for him. TCU and Baylor were his only bad games. If I remember correctly, he actually sustained the rib injury against TCU since that was before the second bye week.
Ironically, Sam threw for more yards, had more passing touchdowns, more rushing yards, and a higher passer rating in 2019 than in 2018. He had more interceptions and less rushing TDs, but you still believed Texas had a chance to win every game, which couldn't be said during that three-year time span before he stepped on campus.