Film study question - what do professionals do?

Seeing a bit of a divide among authors, podcasters, and acting teachers on this topic and am highly curious as a beginner looking to improve between classes and performances.

• One side says that you should be studying and breaking down film like an athlete or student in other disciplines would - the clearest approach I've heard is to read the script for a part, make choices for your interpretation of the part, then watch how the actors deliver them and compare.
• The other says that watching performances is neutral at best - you don't know what you are looking for unless highly trained and you are too just swept up by the emotions and movement of the film.

Is there any consensus on this? Too individualized and not consistent to tell?

TL;DR: Looking for the most effective methods of improving my craft when between workshops, classes and auditions and heard that "film breakdown" by comparing your script choices to the screen can be helpful.

Thanks!!