The mission is to organize & make available the world's information... which coincidentally is equally compatible with increasing shareholder value.
I think most people dramatically underestimate the amount of resources Google invests in all sorts of programs (including R&D, charitable donations, education, partnerships and so much more) because 1) they don't use it as a negotiating tactic, and 2) the cash cow of the ads business provides an enormously long leash for experimentation and.
Even with Apple, which has more than double the cash (and cash flow), doesn't have this flexibility because of its business model. As a hardware company, volumes, revenue & margin are predictable and anticipated, baked into the stock price with an assumption of -- for the last few years -- dividends. Amazon is at the other extreme. Until very recently, as a result of AWS' runaway success, Amazon had posted negative-to-zero profits for its entire history, reinvesting nearly 100% of free cash flow into business expansion.
No matter what you might think of Google, among the huge tech companies they're unique in their ability to spend enormous sums on things that absolutely do not directly increase shareholder value. The belief within the company, and within the investment community, that some of these moonshots & experiments will eventually stimulate stepwise returns are why they continue to run this way. It's cultural, and ultimately, one of the foundations of "googleyness".