Only because we only know it as trackless. But if you think about the fluidity of busbar rides like Spider-Man/Transformers, MiB, and Dinosaur/Crystal Skull, it becomes a lot easier wonder why Rise “had” to be trackless. Apart from a brief moment after load, the interaction between the RVs is irrelevant to the point of non-existence.
Which, I think, is why Universal may not be itching to go “trackless.” Creative doesn’t get enough credit for how well the marry an attraction’s story with the ride system. It’s not often they over complicate an attraction with ride technology that isn’t essential to the story “just because.” Which, if you really look at most of the trackless rides out there, is what often happens. The trackless element in Antartica at SeaWorld is frivolously used. Same with Rise. Hunny Hunt, Runaway Railway, and Beauty and the Beast overly rely on the “dancing” gimmick which often stops the rides’ flow dead. Mystic Manor and Symbolica are some of only rides that actually make the trackless element “critical.”