Comics needed twelve overlapping revolutions to survive as a medium
McCloud frames the entire book around twelve necessary shifts he believed comics needed to undergo, spanning how the medium is perceived (as literature, as fine art), how it's produced and governed (creators' rights, industry practices), who participates in it (gender balance, minority representation, genre diversity), and how it's made and delivered in a digital age (digital production, digital delivery, and digital comics themselves as a distinct form).
His point in grouping these together, rather than treating technology as the whole story, is that a medium's survival depends on cultural and economic conditions as much as on new tools; a comics industry that mistreats its creators or excludes half its potential audience will struggle regardless of what platform it's distributed on. The digital chapters get the most attention and the most specific argument, but McCloud insists the cultural revolutions matter just as much.
Takeaway: a medium's future depends on who gets to make it and who gets treated fairly, not just on which technology delivers it.