Alcaraz should be winning, but he is playing very inconsistently. Zverev is playing neither great nor bad, but often in tennis, the most important thing to do is to not beat yourself. Of the two, Alcaraz is beating himself more than Zverev.
Yeah about to do something so probably will miss the end of the match, but Zverev is not playing world beating tennis. He’s playing solid don’t beat yourself tennis, and Alcaraz can’t get out of his own head.