The "Is Manga going to take over American Comics!?" argument is already outdated.
They're both losing to webcomics now.
Which doesn't mean either is going to go completely out of business, cease to be or get devoured by webcomics... It's just like... yeah, manga didn't completely overtake American comics in the early 00s like some people said it would, prompting Marvel to make the hilariously awful "Mangaverse", it just became a more popular format for comics with an audience that felt like American comics weren't really catering to them, and it was also more affordable. Now the only bar for entry on webcomics is "do you have a phone", and due to how they're made, webcomics are a lot more able to feel genuinely up-to-date with culture, they've attracted a big audience that just feel like both American comics and a lot of manga have become impenetrably insular, irrelevent to young people due to too much adherence to established tropes and archetypes that are popular with existing audiences, and expensive.
Currently, if you're not a super well-known creator already, most pro comics people in the English speaking world agree that the money in print comics is in children's graphic novels; it's the only area of print comics that's actually growing in places like the US and UK, largely because you can't easily monetise kids digital comics due to various regulations (they can't have a user profile, they can't be advertised to, they can't pay for microtransactions...).
So we have DC and Marvel dipping their toes in both the webcomics waters and making books aimed at a younger audience, and we also have experiments with manga made in a webcomic format, or the Shounen Jump App (I love the shounen jump app, it's a genius way to beat scanslation, by releasing a better, higher quality translation on a convenient app the day of the Japanese release for just £2 a month. Hell yeah I'll pay for that!). It's not going to replace floppies and trades, or weekly jump and tankobon completely, but I think in most parts of the world, we're going to see the same trend as in parts of Asia, where the "biggest comic publisher" is Webtoon.