Do not negotiate with terrorists. They need to build this datacenter somewhere, so if no city/state yields to their demands they will build it anyway, without any tax breaks.
In practical terms, Google (or Amazon, etc.) wants tax breaks but also wants a desirable community to help recruit and retain talented employees. If a community so impoverishes itself via tax breaks that it can’t afford to remain desirable, then nobody wins. Abuse and wildly perverse incentives are of course possible, but absent those scenarios, there’s an equilibrium between private incentives and public investment that certainly exists.