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.