As someone who read some Marvel as a kid, but stopped around 12 or so, I would come back and read some if:
- there was one title per character (obviously, teams can have their own separate title too)
- understanding storylines did not require me to read multiple titles
- related to that, crossovers should be genuinely rare events (once every couple of years or so)
- sell them in supermarket aisles, at newspaper stands, etc.
- stick more ads in to knock down the cover price significantly.
- new issues every other week. Weekly, preferably. Cut the page count if need be (cutting cover price proportionately of course). Scheduling should be bullet-proof consistent.
You can summarise all my points as "make comic-reading a casual easy past-time, not a collector's hobby/obsession". At the moment, I look at the comic world and see a business model I don't want to engage with as a consumer. As an outsider looking in, it seems like an industry trying to squeeze ever more money out of a shrinking readership, by preying on their completionist neurotic tendencies. That may or may not be an accurate gauge of how they work, but that's what it looks like as a casual would-be reader, and I want no part of that. I'd just like an escapist comic featuring my favourite characters to dip in and out of.
My hunch is that they'd also make more money from a broad (if shallow) readership than from the narrow but deep one they currently seem to have, but I have no experience of their industry to support that hunch.