I think this story is completely missing the point. Most companies would be risk adverse and would want the city to shoulder the risk with a bond and increased taxes to pay for it. It sounds like Google is proposing a form of equity compensation where they are paid based on performance. The metric for that performance just happens to be tax revenue generated by the project. It could just as easily be some non-monetary metric correlated to city revenue.
With the convenient side effect that you have to cancel some megacontract if performance is not what you expect. With everything else it's: "hey, your contract has run out after x years, reapply and make sure you do it better". Alphabet seems more like: "well, you have to pay us for our expenses 20 years back. you know, you owe us. do you really want to break the contract". It's all about power and making a dent into public law which today is basically quite good at preventing Manchester-like capitalism (at least in the developed world, even post-Reagan)
