[snowwrestler]

I think this depends on the structure of the series.

When all TV was by appointment (no easy way to rewatch), series emphasized self-contained episodes. You could watch half of the episodes of any season of Star Trek or TNG and still enjoy it. Same with other popular shows like Magnum PI, Law and Order, etc. There was some ongoing charater development, but it was pretty slow and minimal.

As rewatching got easier (essentially once market penetration of VCRs got high enough), popular series started introducing more serial story lines. X Files is a great example; it started off with mostly "monster of the week" self-contained stories, and then over time added "lore"--ongoing serial storylines.

On digital platforms, watching and rewatching are basically the same thing, so a series can be 100% serial storyline. Essentially, they are very long movies that are released one chapter at a time.

This has affected movies too. There's no way something like the MCU would have worked as a concept without very easy ways for viewers coming into the middle to go back and watch or re-watch earlier movies.

[dunnevens]

Soap operas in the age of pre-internet appointment television dealt with this problem in an interesting way. If you missed an episode or missed the entire week, you could always buy the latest issue of Soap Opera Digest which would have a summary of the week (or month's) story arc. Once a year or so, there would be magazines which would summarize the entire story arc of the show so new viewers could catch up. On a side note, if anyone is bored at work today, look up the Wikipedia entry for a long-running soap, like Days of Our Lives, which will have a synopsis of the entire story. It's quite epic, silly, and tawdry with a decades-long, no-breaks, no-jumps storyline.

I think for prime time viewing, Hill Street Blues was the first semi-serialized drama intended for viewers outside of the soap market. It had an interesting structure with A, B, and C plots. A plot gets resolved in a single episode. B plot is a 3-4 episode arc. And C plot lasts for the season. And then there was continuity from season to season. The show was decently successful, and paved the way for what we have now. One thing I find interesting is how many older viewers at the time thought it was too fast paced, too complex, and didn't enjoy it. They were too conditioned to the episodic norms. I'm sure the show would seem slow now to modern binge watchers.

[ghaff]

The other thing going on that probably affects some of these complex serialized shows is the Internet/Web. I suspect a lot of people would drop out of some of these shows that you almost have to watch each episode carefully twice in order to understand what's going on. Recaps and discussion boards make some of these shows more enjoyable and comprehensible IMO.