That assumes you just keep the cash. I think what they meant was:

First year make 400k, buy 200k worth of something that is not just one egg basket. But because it's salary you do that every ~2 weeks so you end up with hopefully more than 200k by end of year already too. Continue example over the other 3 years.

Yes the upside is smaller as I would assume the broader market part would return less in the upside case. The point is that your downside is 'better'. Instead of your tech stock tanking over proportionally you'd be down less or be even or could decide to stay in cash mid year as markets tank and interest rises or buy something else like a house. It basically allows for better 'control' and a less bad worst case at the cost of being able to 'win the lottery'.

Of course you are right that just buying one stock, even if not your own company from the cash is actually worse overall. If you were gonna do that, just get the RSUs.

They asked if you could "end up in the same boat" by getting paid the same amount in cash as RSUs. You can't. There's a common misconception that RSUs are only more restrictive than cash, that if you got paid in cash you could just use the cash to buy the stock and end up in the same position. This is just not true.

RSUs have downsides. That was never in question in this thread (as much as people keep affirming it).

RSUs also have financial upside over the equivalent amount of cash. That's the thing people keep trying to explain but also seems to get brushed off.

$100k cash and $200k RSUs per year in a stock that increases by 10% each year: after 4 years I have $400k cash and $1.171mm in stock.

$100k cash and $200k cash given to me at the beginning of the year to buy the same stock for 4 years: $400k cash and $1.021mm in stock.

They're just not the same. RSUs have leverage. They have upside and downside.

Fair enough on the exact same boat. Very unlikely given the companies that usually have RSUs in that value range. You would have to get RSUs in a company that is less likely to go up than what you could invest in with the cash.

For a less sky rockety company that still offers RSUs I would take my chances with the cash and actually ending up in a better boat.

You can also invest the RSUs that vest or keep them. In my example I assumed you cashed them out instantly and did not invest the resulting cash. So while the cash looks better with investments so do the RSUs.

That also means the risk of RSUs is also not as high as you paint it out since you don't keep them for 4 years. After the 1 year cliff you can sell them as they vest. So you're only risking future money rather than money you've already gotten. Unless the stock goes below the original stock price then you're still ahead. If it does then you either get a top up or find a new job.

I see it this way: with RSUs you are betting on one egg. Your company. There are things about RSUs that make them more attractive than getting cash and betting on another single egg. If I can get cash instead I will. I don't count the RSUs as a decider in that sense. Given my risk tolerance I'll take extra cash if I can and invest it into multiple eggs instead. Over the past 10 years that probably would have made me loose out on money. We will see how it goes in the next few. When all tech stocks are tanking I bet it's going to be hard to switch to another company where things would be better. Having bought stocks that have paid dividends through many years of recessions with the cash I got seems better to me. Of course you could have sold those sweet RSUs and bought more of those same dividend paying stocks than I can. Power to you if you did. Somehow I doubt most people that choose the RSUs have done that and instead only cashed out to buy a house or a Tesla etc. Not saying that's you or everyone. I drive a 11 year old car I bought used. And would even if I had taken RSUs ;)