I disagree with this premise, that we necessarily need that "end" state in content consumption. As many things in the real world have an end state as (effectively) don't. I can finish a game of Risk, but I will never finish building relationships with my friends. I can finish a pile of tacos, but I will never finish seeking an understanding of my existence. I can finish re-watching all Star Trek series, but I cannot finish learning about the opinions and ideas of others.

Some activities just go on forever. We learn that certain activities have an end and others don't. The ones that don't we give attention to in a manner proportionate to their importance. In representing content streams as infinite, publishers are simply mimicking the interminable reality of that activity. Future generations will never have learned that there's a daily endpoint to what you can know about your friend's lives, current events, etc. What a silly proposition!

I (wildly) speculate the feeling that an end state is needed springs from weakness/inability in moderating one's impulses. The end state then is really just a crutch to force one to stop some obsessive activity.

[Edit: removed disparagement of Star Trek DS9.]