The people trying to spin Twitter making SMS MFA pay-to-play as a good security move are causing me actual, physical pain. —Why are you doing this?— Why are you trying to make another silly Twitter business decision sound like it was one for noble and considered reasons and not more haphazard cost cutting, like layoffs and missed rent?

I have a immediate relative (and a few pals) who cannot afford or use a smartphone that runs modern apps, like an Authenticator. I just barely got a few close family members to understand how to copy numbers out of a text message, and what that means, after years of work.

You are letting perfect security be the enemy of slightly good good security, again. Some MFA is massively better than nothing, and all those folks are just shutting it off.