Great so now people need to be rich enough to own multiple phones? Really. The solution can’t be “buy multiple devices” when the average person can barely afford to maintain one working device.
It is true that you do need to be rich enough to own a phone and ~100 USD of something else (laptop or USB), which does put redundancy out of the reach of a large portion of the world. But then they can just use regular 2fa at the expense of not being phishing-proof.
Things being this complicated makes them a non-starter. A nerd vanity project.
And this isn’t a knock on the “intelligence” of the general population. They quite rightfully won’t want to spend their limited time on God’s earth learning about all this.