They do not. You can watch and appreciate different shows. You may want to watch many of them. And watching one show will never replace watching another.

In other words, you've not seen farscape as long as you've not seen it, and the expanse or any other show ever will not change that fact. Hence no show is ever competing with it.

What they're trying to do is to make a competition for your time and attention. But humans don't work like that. Culture is a shared thing. Good shows will be shared and watched while bad ones will be forgeted. If you make more shows than people can watch and share, you're simply wasting money. Which is why it's not sustainable.