It is easy to forget how much space is needed for TM/backstage stuff, or even for maintenance bays etc. I think in the past they did not give stuff like that a lot of thought, so older attractions don't have that much of a TM breakroom, but newer attractions often do. You also need a lot of backstage roads and walkways, as well as access for emergency personnel. Dinning places too, a lot of them have to serve TMs as well, so that requires extra space too. Then there is storage for both merchandise and food and beverage. Hangars for all sorts of stuff. Wardrobe, which is huge; and a wide variety of TM services. Back of house is really complex, and can be quite bewildering to say the least lol.