I only use YAHOO for their sports section, but since they revamped it a year or so ago, it is garbage now...
Yahoo mail was horrendous for spam and retailers. They had a good sports page until the UI redesign and it became literally unreadable. Had to be one of the worst ever redesigns. The news feed is now fraught with clickbait ads.
It's really a shame what the organization has become. Mayer has driven it into the ground.