I think the problems between Christiano Ronaldo and Erik Ten Hag have been resolved and they are in good terms to work together and function as a team. I would have listened to speculations of Ronaldo leaving Manchester United in the January window if the sentiments remained but since the issues seem to be resolved I think Ronaldo's departure looks unlikely to happen and he might be willing to stay back and help the team through the season. It was why he came to Manchester United in the first place
So far, no more hot issues after the bench incident. Ronaldo has got playing time back as a starter, his relationship with Ten Hag seems to be going well.
I hope, if he has more playing time, his form will slowly improve. however, related to speculation leaving Old Trafford in the January transfer window. as you said, Ronaldo's departure seems unlikely for the various reasons that go with it. besides that most clubs are reluctant to bring him, in addition to a large salary, unstable performance. So yes, it's better for Ronaldo to stay with Manchester United.