Using one of the companies that did well over time as an example isn't really fair. There's lots of companies where those stock options would be worth a moderate amount, and even more where they would be worth nothing.
But you should be looking at RSUs as a funny money kind of thing.
I think RSUs are more valuable to companies, which is why they do things this way. And that's fine. But it doesn't mean they are more valuable to me.
Of course nobody would actually do that with the cash, because most other things (like buying an index fund or stock in one or more competitor companies) would be a smarter thing to do with it.
Be careful with this... if we're talking about diversifying your risk, there's a good chance that the stock values of your employer and of its competition in the same industry are positively correlated modulo some market events. Better to buy stock that is likely to be independent of the industry that derives your primary salary.