Their and my wording is pretty specific though, and it doesn't say 'it's so handicapped as to be basically a dumbphone" it says it doesnt work with a lot of specific common proprietary apps and I don't think those are interchangeable because it makes it sound way worse than it is. It's not that you can't do messaging on it, it's just that facebook messenger/whatsapp specifically will be more of a hassle because there isn't a native application. Others like Signal, Matrix, even some proprietary chat apps aren't so bad. Telegram has a native app that many people use as well, I think it comes preinstalled on some distros. Banking is similar. Similarly your exact bank might or might not work with it, but many will work great in an android container or in the browser (mine does, quite well, and its not a major chain).

It isn't there for every use case, but it is workable for more people than you'd think. Not everyone depends on fb messenger and instagram, or at least not in a way where they need push notifications 24/7 and a browser won't suffice. it's full of compromises but mostly not an outright lack of functionality. I use mobile linux, and while many people don't/won't find the compromises worth it currently, it isn't that it's simply incomprehensible to them, they just have to value the things it does bring to the table more than the compromises. A solid % of the people you see online talking about it are people with little linux experience but who are making it work for the sake of privacy, etc. Shit the guy I bought my device from was an older guy, some kind of libertarian, but not a linux/computer geek, just interested in privacy, and he had been daily driving it.