While reading comics today, I decided that Marvel and DC both need three lines of comics.
1. Cinematic Universe - used for marketing movies and bringing in new comic book readers.
2. Main Universe - Complex continuity, big events, all the mainstream cape stuff
3. Other - Out of continuity books of all sorts, with an eye towards new properties, new takes, and new talent. Elseword/What If books and series go here. Vertigoesque stuff, too. Non superhero stuff, as well.
Both publishers are trying to be everything to everyone, and it just keeps being a mess. When older reader's desires are diametrically opposed to new reader's desires, it's crazy trying to service both inside the same comic line. That's why we have the constant reboots, to give the new fish a place to start. But Marvel never quite goes whole hog, so it never quite cleans up its continuity, and DC blows up everything so regularly that it feels like we have a new round of origin comics every two or three years.
Let the main universe line run and run and run, building up the gooey continuity complexity and hereditary hero lines that long time readers love, and just reboot the cinematic universe every so often to coincide with whatever is being done with the films. Use it to draw new readers, and feed them into the main universe.
And, of course, all of the lines need to do a better job of catering to younger and more diverse readers, if the industry wants a future.