The problem isn't that Google just says, "Hi, donate time to us, your corporate overlords, in exchange for nothing." Instead, they make a very reasonable argument of, "You should help your teammates and colleagues."

Imagine that you're on a team with a junior developer. Their feedback is basically worthless to promotion committees because they're low-level. If they say, "Hey, can you help me understand why my code is crashing?" the selfish answer is, "No, if I spent two hours helping you, the benefit I provide to you is not measurable or quantifiable and won't help my case for promotion." But it would also be kind of miserable for everyone if you constantly avoid helping your teammates and only do the absolute minimum required to avoid standing out as egregiously unhelpful.

"You should help your teammates and colleagues produce more value for the company because we hired you to produce value for the company" is an argument.

Now if the company's employee evaluation process doesn't recognize the second-order value you produced here then that's the company's problem, not yours.

I think I personally skewed too far into trying to do unmeasurable things, but I feel like it would be miserable to live on the other extreme where you only do things that are measurable and benefit your career.

Where does that thinking end? If I don't feel like finding a garbage can, should I just throw my trash on the ground as long as nobody sees me? After all, it's the city's fault that they haven't set up incentives to prevent me from littering.

I would argue if you aren't able to see why the education system produces that result on purpose then you don't understand how the economy works.