Bargue (developing freehand accuracy, not sightshit) is the path to mastery. If you do not develop an accurate eye then you will not make it.
You need to be able to look at anything and know that with little conscious effort you could copy this down accurately. That is a basic fundamental skill.
Imagine this hypothetical scenario:
>You want to do a study of your favorite artist
>You try your best to do a lay-in of the painting that you can paint over, but you unknowingly make a bunch of small proportional mistakes
>Now you try to paint over it and study the painting. You try your best, but it keeps looking off. You can't tell if it looks off because you're fucking up the painting or if it's off because you fucked up the underdrawing.
You need to be able to say to yourself, "The drawing is solid, I know it's solid because I can do an accurate drawing, and if it looks bad at this point then it's because of poor rendering, bad values, etc, and not because the proportions are just fucked up." It is extremely difficult to learn and grow if you are struggling with multiple things at once. As much as you can, you need to isolate it down to one problem at a time
