Good for Germans then. Slovenian banks won't let you use physical 2FA authenticators (for personal accounts and maybe even business ones at this point) anymore and will also require you to constantly update their stupid app (I've had to replace some otherwise good phones because the OS version wasn't supported anymore).
There are plenty of banks in Germany which offer over-the-counter services, if you prefer to do banking as if it's 1999. Most of the time, when people say it's impossible to live without a smartphone, it's actually only impossible to enjoy the conveniences of the internet without a smartphone (at least in Germany). Besides these rentable scooters, I can't think of anything that actually requires a smartphone. Sure, you'll miss out on a lot of conveniences, but I remember a time where that was the norm, so it's not like it's unreasonable.
To add to the sibling comment, you are also ignoring the fact that in 1999 nobody had those conveniences, everybody was on equal ground. In 2026, if you handicap yourself by rejecting those "conveniences", you will be met by friction at every step - lower productivity at work, impatient looks from your family members etc.
The comparison to 1999 is not entirely accurate. It doesn't take into account that most physical banking locations closed down. At least here in Belgium for example, you have to go far to find one, and it's often on appointment only.
The question of how useful or not it is is orthogonal to whether it is the "fault" of Linux. Users who can't use it because something they need just doesn't work won't change their minds because the blame lies elsewhere.