As I overheard a fan saying at this year's Italian Global Series television festival in Rimini, Star Trek was one of the first TV franchises that you had to own physically in order to see the entire thing.
With so many different iterations of the overarching IP — from the classic 1960s series to Star Trek: Voyager, and more recent additions such as Star Trek: Strange New Worlds — it's not surprising that this has been the case for almost 60 years.