- The preponderance of big campaign-length adventures like Curse of Strahd (which, for the sake of brevity, I'll call Epics) is bad for the hobby, and shorter adventures (which I'll call modules) would be better.
- The main reason is that with modules, you get a sense of accomplishment. You went to Do A Thing, and then you Did A Thing, and now A Thing is Done. Then you can move on to do A Different Thing. But with Epics, doing The Thing takes a really long time, and you're likely to get distracted long before The Thing is done, either by real-life issues, by not being able to keep track of everything that's going on, or by getting distracted by the new shiny.
I think this misses out on a critical point.
Doing A Thing comes in different flavors. Doing One Small Thing has a lesser impact than Doing A Huge Dramatic Thing.
Is the preponderance of multi-volume fantasy or sci-fi novels ruining the publishing industry, which should move back to short stories that anyone can read quickly? No--because they serve different needs.
Some people get far more out of running several modules, both for the reasons you've cited here and for others. Other people get far more out of long-form narratives: they have the
time to build up themes, to establish ongoing relationships (good, bad, or ambiguous) with other characters, to show how a character evolves in response to a complex threat rather than a simple one.
As you say, the issues are that the module-in-theory doesn't have the limitations that the module-in-practice usually does. In practice, they become very formulaic, lessening the already reduced impact; they tend to be scattershot, requiring a great deal of effort to "stitch together" something interesting; and they are all too often Generic Dungeon Crawl #36 because you have to aim for the largest market slice if you want to succeed.
As for ways to fix this? I can think of one strategy that, in a certain sense, would try to
hybridize the two models:
1. Gather a team of writers, say 5-8, who will be paid for a block of multiple adventures, not just a single one.
2. Have the team agree on an overall, between-adventures set of events that unfold. Some of them will be actual adventures in the block, others will be general current events.
3. Each author makes a series of adventures that
loosely link together--you don't have to do every step in the sequence, but if you do, there are fun bonus bits.
4. The authors are paid in part for the collective sales of the whole block (or phases thereof), and in part for their personal contribution. This way, even if one specific adventure just doesn't sell as much as the others, it doesn't result in that author losing their shirt, but you also don't take away the success of someone who wrote a wildly successful one.
If this works, it approximates the best of both worlds. You have opt-in adventures across a span of levels (so every DM has
something they could get value out of), while still having a consistent "background" for things to play out against. You get a light touch of the "Epic" linking story between things, but you don't have to engage with that if it's not interesting to you.
Obviously, folks who just want simple dungeon crawls and folks who want complex plot writing will be best served sticking with adventure modules and adventure paths, respectively, but these adventure "blocks" could address the issues without totally giving up the strengths.