That is true. But the remaning qustion is why HALion (or UVI for that matter) is not as popular as Kontakt. At least one reason is how the file structure is integrated with the GUI. Kontakt is far better here. Another reason is that installing a new library, or an instrument through the file system of Kontakt, is extremely easy, whereas in HALion it is something you need a bachelor degree in engineering to figure out. The sound of HALion is great, but it sucks in both user friendliness and in friendliness towards any 3. party developer. Kontakt on the other hand has an open philosophy towards 3. party developers. They even offer the developers an authorization system that makes the libraries avialable for the free Kontakt Player. Native Instruments developes a huge variety of instruments for Kontakt. Steinberg just a handfullfor HALion.
If I could go back in time I would never have bought HALion 5 as it, due to cumbersomeness, never gets any use, despite the great sound. But great sounds are avialable elsewhere too and my life is too short messing with HALion.
However HomeGrown Sounds has a couple of sets for HALion. Good luck trying to install them.