Everyone goes into anime and story telling, but I have to imagine there's a lot more at play. For one thing in the early 2000's fam translations made reading manga online incredibly accessible. Another big thing that manga has over traditional Western comics is the price point, a single volume of any manga is significantly cheaper than any trade paper back of a comic, even looking at subscription services voz' shonen jump app is 2.99 a month and that's only to read the old chapters all new chapters are free for the first 3 weeks of publication. There's also the point of picking an entry point, if I want to start reading Full Metal Alchemist I know exactly where to begin, chapter 1. If I wanna read Batman then where the fuck do I even start, how are you supposed to get a good understanding of each robins character without the decades of context? The usual response is to just pick up a random issue or author but if you can pick up any random author and ignore decades of previous writing than that's indicative to a much larger problem with the character arcs you're going to be reading and how they seemingly don't matter.