It is absolutely UNACCEPTABLE to be forced to use either the phone or another e-mail address to sign in
I don't know in what parallel universe yahoo's programmers live, but it's simply unacceptable to be forced to use another e-mail provider or an app on a mobile phone to sign in to yahoo. What's next, tell me, will we need to bring in a neighbor to confirm it's us ?
How does signing in to YAHOO mail needing an access code from ANOTHER MAIL PROVIDER make any sense ?
Control freaks much ?
Improve the ******* technology, and hire PROGRAMMERS not politically correct people, and SOLVE the security on your side, not by forcing 2 step, 3 step, secret code, account access code and other kind of nonsense on your users.
You would all be out of your jobs in a single day, if anyone with 2 functioning braincells would supervise you.