There are quite a few of them. Sat in the kids section of bookshops. My son reads them.
Millar has told us plenty of times here that he gets sales spikes on his stuff when a movie is made but it’s all in trade sales in bookshops (and their charts show online at Amazon).
I think there has always been an issue with converting other media success to comic shops because they system is somewhat niche. Which do you pick up? where do you buy them (due to costs comic shops are often in obscure locations or your town may not have one at all)? when will the next one come out? (even long term comics fans get confused with that).
I don’t really think the success in issues of Star Wars is coming from far outside the existing fanbase. 90% would probably be a low estimate of how many superhero fans also love Star Wars. They put A list talent like Aaron and Immonen on the books so they sold a load.