When I log in, I am repeatedly sent to a page that says I must enter a phone number to be used for account recovery purposes. It's also labeled as "required," and won't let me continue with the login without entering a valid phone number. I've previously encountered a similar issue where Yahoo was demanding another email address.
I found a way that I can bypass it and access my email, but it's a concern that Yahoo is "requiring" other email addresses or my phone number before it will allow me access to my account. Yahoo Mail is a "free" service that gets its revenue by adding advertisements to the web page. Asking for my detailed contact information on a pretext of account security is reprehensible. Ask me for a code word I can enter to verify my identity, or a series of verification questions like reputable companies use.
There was a story in the news recently about a social media platform that was fined for asking for phone numbers for "account security" but which was actually using them for telemarketing. I don't remember what company it was. I will NOT give Yahoo my phone number.
One other thing. If my spam folder is empty and I open it, recently Yahoo has started spamming me with videos inside the folder frame. Really? I check the spam folder and they think I'm so bored that I'm going to watch whatever video they put in there? Fail.