The argument that square format is a waste is just a rubbish. Is the 612 or 617 format a waste?
For those who prefer the square format or 617, any other format is a waste, same rubbish argument.
Someone argued that Ansel Adam used HB square format, and yet none of his print is square. Good observation, but what does it prove?
There are a lot of professional photographers shoot and print square format.
However, as long as the small formaters (35mm or sub-35mm format) are the main driving force, I can understand that 2x3 or 3x4 formats to be the easiest/only sell for quite a while.
Even the key Med formaters (Mamya + Fuji) are only good at 6x4.5, I can't see how they can be interested in square format, even the 49x49 cropped format.
I shoot 35mm full frame DSLR, but 24x24 ends up to be the majority. To me 36mmx24mm is a real waste, but so be it.
Maybe, some sub-35mm formaters may find 24mmx24mm to be a sweet spot between the full frame and 1.5x cropping.
Or, it maybe between the 1.5x cropping and 4/3rd: 16mmx16mm.