On History: Artifactness
I'd say that beginning with the Marvel Masterworks and DC Archives, though, things started turning around and publishers really began to see the viability of a strong reprint program. Particularly as they got into chain bookstores, and Amazon came about. Add into that mix the prospect of digital comics, and the need for obtaining every individual back issue in order to read an entire series drops to essentially zero. If you're only interested in reading the stories, you have no need to track down the original issues.
What I find interesting now is how independent creators react to that notion. On the one hand, you have those that take the same basic tactic. They perhaps roll their comic out initially as a webcomic, then send individual issues over to comiXology to view in their platform, and then Kickstart a trade paperback and/or hardcover collection. Their concern is getting their story out there, and they really don't care how you might prefer reading it.
The other approach -- much less common as far as I can tell -- is to embrace the artifactness of the comics they produce. In most cases I'm aware of, there's an element of handcrafting each individual copy. Maybe it's got a unique origami-style folding process built into it, or maybe each copy is screen-printed by hand, or the covers are cut by hand to match the artwork. Chris Ware's Building Stories would be an example of a mass market version of this; he's expressly noted that he's very fascinated with the physicality of the comic as an object itself, and he specifically crafted Building Stories with that in mind. Hence, the variety of formats inside that bulky box.
We're at an interesting point in comics history where we're actively witnessing this transition from comic-as-both-story-and-artifact to comic-as-story versus comic-as-artifact. I dare say we're at the tail end of this transition period. Publishers (driven by readers and retailers) still seem to cater to the comic-as-both-story-and-artifact model -- that's why we still have monthly floppies for stories that are written/designed for "collected" editions. There was a period where creators were still crafting monthly stories, and those would be collected in 5-8 month arcs, but I think we're largely now where they're actively creating longer stories and just try to pace them in a way that breaks up into 20-ish page chunks. I suspect they'd switch over to more of a book format if not for the remaining readers who continue to buy into the monthly "artifact" format, despite the TPB generally being a cheaper option.
The question is mostly a matter of when these monthly readers (who one presumes to be a slightly older demographic) drop off in a significant enough quantity that publishers switch over entirely to the book format, and the comics that will still cater to the artifact aspect will largely be just those hand-crafted books by individual creators.