Literally - you can pick out English longbowman bodies from the shape of their skeletons

I "fire" traditional recurve bows and honestly it ends up being a lot of core, back, and your front side shoulder, but this image is funnier.

I guess also another thing that gets me is when they are fire from the hip, with no anchor point. You draw back the bow to the same spot every time, then move your bow hand to aim. Radically changing how you draw, while hitting precision shots at varying range is like John Whicking archery, but nearly everyone with a bow in movies can do it. And they almost never wear gloves on a bow that has to be hundreds of pounds of draw to go through armor. How are your fingers not worn to bone?

Also arrows are pretty custom depending on draw weight, tip weight, draw length, and there are various types. Where do these perfect arrows you need all come from, hrmmm Legolas?

I am now realizing I took this meme way too seriously, but I've already typed it up, so here we are.

I agree, but it’s obviously done for the tension in the movie. It wouldn’t be as exciting, if the archers were just chillin’ while the Uruk-hai were charging. 😄

Short answer: no, they don't.
Modern compound bows use that cam to lessen the power needed to hold.
Older bows are like holding a spring extended, the further back, the greater the force needed.

By modern I take it you mean compound bows. No other types of bow have that. The force you need to pull back is at its maximum when at full draw. The exact scale of 0-100% through the draw varies with different bow designs, material and even age as it can permanently deform with repeated use.