Apple takes CSR very seriously, and is very serious about investing in projects that make sense, and make the world a better place. Elon is a great match for the vacancy. Will Apple ask or select him? I don't expect it to happen, but it's possible.
Google lacks focus, and prioritizes and invests in pie in the sky ideas (moonshots) to change and improve the world.
Apple focuses on projects that can be accomplished in a realistic time frame, that can be produced in large quantities very quickly, have a reasonably high probability of being successful, and fix real world problems that seem impossible to fix. (Curing diseases, tackling climate change, and transitioning the world to an economy that isn't dependent on carbon emissions by 2050).
It would make a lot more sense for Apple to invest in Tesla than for Apple to buy Tesla.