He's been better this season than most make out. There seems to be this idea that he's been shit all season, which really isn't the case. Don't get me wrong he's certainly had some shit performances, but overall I'd say he's been average rather than terrible.
However, I do think it's a bit difficult to compare these last two games with all our previous ones. We've actually played with a more normal midfield setup in these two games, which instantly makes it easier on Amrabat than what whoever has played there previously (himself, Casemiro or Mainoo) have had. I tend to think Casemiro would also have looked better in these last two games if he'd played in his normal position.
Also, while Amrabat did do quite a lot of good things in this match, he also did some bad (including what could easily, and probably should, have been conceding a penalty).