Data harvesting is a lucrative business. You don’t need to have a good product with todays internet, you just need to have access to a lot of insanely personal data, and yahoo has both an expansive advertising network and hosts hundreds of millions of email accounts. They're just Google except they don't pretend to care about anything else

Yahoo Auctions is still massive in Japan.

Jason Scott compared "we've been acquired by Yahoo!" to "we found a lump."

That was easily ten years ago.

They can keep shuffling along, though. If you don't have to pay for active development of features, maintenance of their existing product lines is relatively cheap.