It's pretty shitty for a company to force someone to use a phone app or go to something as vital as a bank just because they won't let the customer access the website. And there are plenty of reasons why someone wouldn't be able to go to the bank in person every time they needed to, or at least it'd be extremely inconvenient to (especially for small things like checking your balance or transactions). Not everyone has a phone either.

Change your email provider? Run your own email like people should?

I've never deleted my email before but I'm pretty sure that means losing access to your entire inbox that you've likely had for years and having to update your contacts, the emails for all the accounts you have under it, etc. And being blocked from the website means you won't be able to do any of those things through the official website. Does device atteststion prevent you from accessing your email through third party clients?

Also, it's not exactly easy or practical to host your own email. And for many people that would mean spending money on servers. I read a blog post last year of someone who gave up hosting their own email after 23 years doing so.