But we don't have anything like FF as an alternative to go from Android. Especially considering banks require "certified OS".
I also switched banks so I can use my bank card as the 2FA device, similar to CAP. [0]
[0]: https://en.wikipedia.org/wiki/Chip_Authentication_Program
Just observe that the key factor is to be independent from Google and then the only recommended devices from their side are exactly google devices where nobody here can have an idea of what is modified inside them.
You'd be better off supporting other distributions like Calyx, which have no problems in supporting other devices like the fairphone and so on.
Those links don't really help your case, to be frank. Nothing strcat says reads as incorrect or even particularly controversial, they have personal beef with CalyxOS but their criticisms of the choices of the project are largely on point. They're justifiably upset by the mental health accusations too, it's kind of a joke that one of those people in the thread tried to gaslight strcat about how these accusations are somehow not a recurring issue when I, as a third party observer, have seen it come up all the fucking time.
Meanwhile, you're imagining "attacks" on GNU/Linux phones, when most of what I read from them regarding those was sober and reasonable, if not particularly positive, but they're allowed to do that. Their priorities are clearly security and none of those phones really have any.
As opposed to a black box from Google, that nobody really knows exactly what it does...