When you're the type of person who commits.
Me, after watching 8 seasons of some idiotic streaming show.

"I just wanted to know how it ends!"

It never really pays off, just read a summary.

That’s what I started doing. Often shows become so convoluted within a few seasons that I’m not even interested in reading the summary to the end
This was me and Manifest.
I started to watch the last season. About 15 minutes in I realized I just didn’t give a shit.
I wanted to see exactly how ludicrous it would end up getting.
I’m glad I gave up after season 2. I kept waiting for something important to happen, but all I ever got out of it was poorly written family drama.
Was that before or after the whole thing turned into a Bible story?
Oh, I’d have to say before. Now I’m extra glad I quit when I did.
I mean these are just the prequel. You knew how it ended before you even started.
And that’s how I disappointed your mother.

That’s how I handled most of the New Jedi Order books, the mainline Star Wars Legacy books that take place after that, and also the Dune books by Brian Herbert and KJA.

The Star Wars books at least sound good in outline form. I’m not about to spend any time reading them for real to find out otherwise. The latter day Dune books, OTOH, sound like absolute shite even in the summary.

I read a bunch of the star wars books that came out after disney took over. They were… Not good. Like 4 out of 15 or so were even okay.
Supernaturals
Assuming you mean Supernatural, while I didn't care a lot for the Leviathan storyline, I'm glad that I made all the way through since it picked up again after except the very last episode which I didn't care for. Ending on the second to last episode would have been perfect for me.
season 5 was suppose to be the true ending, because of kripke, he gave up after people wanted to continue it. outside of 8, and 11, every other season was pretty bad. also jack was apparently shoe-horned instead of using jessie turner as the anti-christ in the show.
Pornhub channel?
I should’ve stopped watching lost when they showed the monster. That’s the moment I knew something was off. But I didn’t and now I’m disappointed.
Me with Picard. Stopped watching I think less than halfway through the first season when I realized it was just a 12 hour movie with a terrible plot and everyone being out of character for themselves.