It sounds like you're incredulous that even banks are being insecure, but history has shown that you can expect banks to be roughly last in terms of competent and secure IT. I trust my Walmart.com account info to be safer than my bank info.
I doubt that most of the people that complain about SMS live in rural areas. It seems to be more of a US thing. The country is so large that unless you live in a city you just won't be able to get data reliably. This leaves SMS as the only form of phone communication that isn't a voice call.
Even installing and using a TOTP app, and configuring it to work with an online login, is a hurdle that a non-negligible number of users cannot pass.
It's better than nothing.
Maybe Starlink will be able to provide a mobile phone service that only offers a data connection one day, and that will be the "disruption" the mobile industry needs.
It's insane. I've heard banks using SMS!!!! To send a code. We have TOTP for that! Or even perhaps a push notification or something better than bloody SMS.
I refuse to use the networking system altogether. No phones, no calls. Of course you do 'need' a number so I keep one handy, but I haven't read a text or made a phone call in a long while.
It needs to die. NOW. Outlaw SMS!