To be frank, I don't think they care about anything else other than keeping people on the platform. Which is not such a bad goal to be had if they tried to achieve that with quality of service, good offering of entertainment, etc. What they are doing is desperately trying to create some long running series where on which people will get hooked and won't be able to leave even if everything else starts sucking. Should this ever happen I think we can fully expect their next step to be reduced amount of licensing towards other shows and movies.

But as you rightly put it, you can't grow forever and ever increasing revenue can only be had in dreams.