Given the sizes of those 2 companies. I'd vote for https://duckduckgo.com/ to be the ideal underdog.

Err, that happened quite a while ago. I think people were rooting for Yahoo just before their (failed) Panama Adsense competitor was released. (I say "failed" in the sense that while it kind of worked, it didn't match AdSense's results)

Your comment doesn't make it clear if you realize just how much bigger Google is than Yahoo. Google is worth $300B, Yahoo around $30B.

I think most, if not all, of those heaping scorn on Yahoo! would definitely like to see Yahoo! succeed and provide some viable competition to Google and Facebook.