If you ask me whether that would be or seem the primary reason for any franchises to occur or just any movies or games to be made my answer would certainly be no.
Franchises aren't launched to promote comics or reading or creative content, but more rather a license or property is milked or utilized in order to make money.
Obviously those things won't neededly be synonymous per se.
Plus if you look at how certain editors and creatives working at Marvel or DC were employed as to guide or mentor in-house talents into becoming comics creators over long periods of time, or how comics properties came to be in earlier times or either nowadays then I would sense much of a difference in ways.
I'm not saying franchises or movies couldn't be made to promote comics, but I am saying that most any of them currently don't seem to be intending on it that much or at all.