It's not always your choice. In my country, you're basically cut off from banking services if you don't own a smartphone. I lived without one for years and had to give in a couple of years ago (second hand but perfectly usable — thanks to LineageOS).
The pain was self-inflicted in my case, but some people simply don't have money for one (as there are lots of people living on 200-250 USD per month or even less — they have nothing left at the end of the month).
If any banking whatsoever then sure, this is a problem like cashless society. But if it's from a set of specific banks that makes sense. I use a smartphone only bank and pay lower costs as a result. That makes sense.
I guess you're right ultimately, if there's choice. But the alternatives get more expensive. Basically all kinds of businesses have figured out they can get us to sell our privacy in return for a relatively cheaper product - and as this becomes the norm, it no longer even seems to be cheaper, it's just that resisting selling your privacy gets more expensive.
The pain was self-inflicted in my case, but some people simply don't have money for one (as there are lots of people living on 200-250 USD per month or even less — they have nothing left at the end of the month).