Yeah writing a synopsis is way more effort than I'm going to put into watching television.
And I think there are plenty of "old-style" shows that had great episodes week after week. Star Trek The Next Generation comes to mind as an old 26-episode-per-year-and-3-month-break style of show that was not only consistent in quality of writing, direction, scripts, and acting, but also featured extremely detailed and high-budget SFX for its time. X-Files is another that comes to mind.
Sure, those are examples of very high-quality shows and not all of them were like that, but then again, I'd say a majority of short-season huge-waiting-gap 6-to-10-episode shows being produced by the content providers like Netflix and Prime, aren't particularly good, either. So the modern short-season-long-gap type shows haven't isolated and distilled some previously unattainable recipe for success, either. There is good and bad, just as before.
The main difference is that previously I could remember the show, with only a 3-month gap. Now, when I have to wait 12-24 months, I often lose interest and move along.
Well, I'm obviously only talking about the shows we'd consider "good" or else there's no point in discussion what impact the format has, because nobody cares and nobody's watching it. Good point about ST:TNG, and it raises a new point about the more prevalent overall story arcs in today's shows vs. the "episode-of-the-week" of shows like TNG back in that era. Many non-sitcoms now have abandoned the episode of the week style and lean into a connected, larger narrative. If you missed an episode of TNG, it didn't matter. If you miss an episode of Stranger Things, it matters. That old format opened the door for some cool excursions into oddball ideas to explore without getting outside the show's ethos. It's harder to do that now, when every show is supposed to be following a central story.
So those long-form shows now that follow a central story are ones that get stuck with slow episodes, or filler. A show like TNG didn't really have filler, by definition, since there was no main story to cling to. However, ST:DS9 moved into the long-narrative-arc format, and had the usual network 22ish seasons, and while there was definite filler episodes, it managed to make them interesting nevertheless. (I know a lot of fans didn't like the darker, less Roddenberry vision of the future that DS9 introduced, but while they have a point, it was still a great show imo.)
I don't mind a tight, 8-episode story, and while it sucks to wait so long for another season, that is not a strike against the actual quality of the show. I also don't mind a 22-episode season, if it's great. As you point out, there have been those shows. But it's not incompatible with saying they tend to have more filler.
I tend not to lose interest in long gaps with good shows, but I certainly understand the frustration of not remembering as much as you want to by the time it comes around. There's a reason I had to do my own reviews to jog my memory o.O! My recurring viewership tends to operate more on what I think about the show than the gaps between episodes. If I don't watch Stranger Things again, it's because I haven't really enjoyed it since s2, not because it's been gone for a few years.
