If the stadium had been built in the south bay, SF might today be saying, "Whew, we really dodged a bullet there", and meanwhile Twitter and Dropbox and Uber and Airbnb would all be headquartered in Santa Clara county and giving them all their employees' tax revenue.
Rather (like in Baltimore and San Diego), the new stadium revitalized a neighborhood whose original reason for being had mostly dried up, bringing enough business to support the (re)emergence of nearby restaurants and other amenities, and those investments in the neighborhood made it an attractive place to have offices that eventually became the new primary source of support for the restaurants, condos, hotel, etc.
The stadium was what broke the neighborhood out of the chicken-and-egg quandary.
The area around Levi's Stadium didn't really have much latent potential waiting to be unleashed.