I've always wondered why rows of 3 seats couldn't be on a slight diagonal, rather than straight across. That way, assuming the diagonal went in a slight forward to back direction, the person in aisle seat will be adjacent to middle seat person's thighs, depending on how steep the diagonal is. Exiting shouldn't be a problem since all the rows are on a diagonal.

The problem with current seating is because all our upper bodies are on the same plane (well we are, but I'm referring to the same vertical geometric plane). My suggestion is to shift the geometric plane of our upper bodies on a diagonal.

I wonder if this has ever been tried. I understand some first class cabins now have seating which is not 2 across.