True but for perspective, there are approximately 4665 rooms in Beach Club (Resort AND Villas), Boardwalk (Resort AND Villas), Yacht Club, Swan and Dolphin. For 2 main destinations - Epcot and the Studios, buses aren't necessary, there are boats or you can walk from that area. You're also walking distance from Fantasia Gardens for your mini golf needs. And that's assuming you bundle all Epcot resorts in one bus route.
Meanwhile, there are nearly 6000 All Star rooms, nearly 2000 AoA rooms and nearly 3000 Pop rooms, and each of those resorts isn't walking distance to anywhere, so you have to always use DIsney buses or a cab or your own car or rental car. And each of those buses make multiple
You're right, for what you're paying to stay in a Deluxe, there should be no need to share resorts, but since you do, it's not much of a difference between bus services between staying at a value and an Epcot resort. YMMV may vary on any given day, of course.