(In case it's not obvious, I've given this topic a lot of thought over the years...)
I would suggest the comparison between modern comics and golden age comics is analogous to modern software programs and the programs of the 1980s.
When the expectation is that there is unlimited disc space and memory available, software programming balloons up to fill that space - offering more and more "features" with each aspect of the program designed to entice a different type of user. Because processor speed, RAM and disc space are not considered germane, tight programming is considered passe. There is no reward for a programmer to write small code.
Similarly, When the expectation is for an open-ended story line, with no restrictions on the number of issues, there is no premium put upon compact, tight scripting. The glitz and glitter of leisurely-paced subplots and sidetracks is rewarded as good comic writing, with something for everyone who likes comics: conflict, physical violence, vigilantism, romance, sex, soap opera drama.
We used to have different comic genres, or different stories in anthology titles to satisfy different readers. Now that's considered passe.
But, and this is the crux of the matter, the bigger programs become daunting, and dauntingly expensive, and users start looking for open-source equivalents with fewer "features" and lower cost, with easier learning curves. Do you really NEED Adobe Photoshop at $600 or will GIMP work just as well for your needs for free?
That's what is happening with comic books. If you can't assimilate all of the backstory in Spider-Man this or Spider-Man that, or can't understand how they differ or overlap, or you just aren't interested in 2/3 of what's going on in any single issue, you're going to go look for some other source of entertainment - probably free on the Internet. It's just going to get to be more of a no-brainer choice: commit $100 to a 30-issue cross-over mega-happening at Marvel, or download another couple of YouTube anime videos or review some free comics on GAC or elsewhere.
Sure, the pamphlets will continue because big studios are willing to underwrite them for their own selfish reasons. But I maintain that the audience for those pamphlets is, quite literally, dying off and it's not being replenished at anywhere near the rate needed to sustain itself.
BD albums with more concise stories that reward writers who give the reader a full story that satisfies will also survive simply because that market is self-sustaining and, surprisingly, growing. Let's just hope that these European authors aren't dazzled by the "freedom" exhibited by their U.S. brothers and sisters and start to think that's what comics are all about. It's a false picture and a false ecomony propped up by outside interests. You need internal support to survive.
Pamphlet comic books in the U.S. no longer have that support.
my 2