Square-format cameras are actually easier to shoot.
Gotta agree - I always wonder why people say square format composition is hard. It comes very easily to me, especially when compared to 2:3. In 2:3, it seems like there is a whole third of the frame that you have to find something to do with.
Decades ago, the Victor Hasselblad company (back when he was still alive) produced an entire series of very small, beautifully-illustrated and well-printed four color booklets on how best to use ALL aspects of the Hasselblad system. I read and re-read those booklets for many years. They had one devoted exclusively to composition with the square format, which Hasselblad was famous for. A camera that sees and captures in square format is very different than a 3:2 aspect ratio d-slr. Unless one has used a square-format camera (Rolleiflex,Hassy,Bronica,Yashica TLR,Argoflex, Maimya 6, Rolleicord, etc,etc) then it is difficult to appreciate how it actually works.
Your comment that ,"
In 2:3, it seems like there is a whole third of the frame that you have to find something to do with." is an astute observation. Yes, one needs to "do something" with the entire compositional space. For many beginners, there's a great tendency to just plop the subject in the center of the frame,or wayyyyy off to the left of right third of the frame, and then snap the shutter. They call this dead space "negative space" in many cases.
WHat's interesting I think is that MANY beginners take photos that would actually be much,much better if they were presented AS SQUARE-FORMAT images, with all that dead, errr, "negative space", eliminated. In web galleries, square-format images actually have a lot of eye appeal,and allow more images to be presented in the same screen real estate.