Remember, editing tape was a major function back then, and big machines make editing much, much easier. I only have big tape decks for that very reason. I need space and the special editing functions available on big machines. Many of the smaller pro consumer or consumer machines have no edit functions on them.IME in studios of some years back, it was primarily about saving space, not sonics.
And BTW, the big decks I saw were mostly Otaris (New York and surrounding area).