Curious about different links,shows,movies

I hope I dont get into hot water here
I am curious about something about these links, all of them. Viki has over 3 thousand dramas, movies and such, which includes licensing and such. and most of these other links don’t.
Hulu is the weakest of them all and this is supposed to be a big company
Netflix, got a lot of the older shows and a few new ones
my new one I found is drama fire, looks like it has a lot, really havent checked
but viki, looks like it tops them all which is fine with me. so again one more time, is this all due to those licensing and who gets them first? if that is the case, what about those older dramas that are close to extinction and can watch them on these different links?