So if you’re the sort if person who’s likely to work hard at a BigCO long enough for most of your rolling RSU grants to vest, then yes, the comp difference is that big.
[0] note that MANY senior people at BigCos are NOT high performers. So beware of comparing to things like Glassdoor comp figures, which are highly likely to be coming from non-high-performers.
The continuity of a big co. can be very helpful from a salary perspective.
And while $300k assumes fairly high performance at a top public company, it's certainly not the upper bound.
[1] https://www.tekna.no/en/salary-and-negotiations/salary-stati...
Possibly even a little low for the Facebook / Netflix / etc tier.
Also, some companies will have target compensation bands (I know Yahoo did) where an increase in stock price will actually result in a smaller additional grant each year.
If I am supposed to make $1m more at Public Company over -- say -- a 10 year period, then that means my salary at Public Company would have to be $100k more per year than at Startup Company. Is the difference between startup and public really that big?