That's correct.
However, I still much prefer RSUs over options in the case where you're joining a large/later stage company. Say you go to a Slack or Uber today. They won't (I believe they legally can't?) issue you options below their FMV (fair market value). They will give you some arbitrary/negotiable number of RSUs and options however. Then consider the following scenarios:
(1) The company then IPOs or is acquired several years from now, at double the current valuation. In this scenario, assuming you 83(b)'d and early exercised, you get the favorable tax treatment on the gains for the ISOs. But you're still out the exercise price outlay. The RSUs meanwhile are worth what they're worth, and you are taxed on them at the higher rate and that's that.
(2) The IPO or change of control happens too soon (less than 2 years from date of grant or 1 year from date of 83(b)/exercise). Your fancy options spread is still just ordinary income with no advantage over the RSUs.
(2) The company IPOs or is acquired next year, for the same FMV. Your options are worthless, your RSUs are still worth a goodly amount hopefully.
(3) The company IPOs at half the FMV of when you joined. Your options are worthless, your RSUs are worth something.
(4) The company fails/does a down round/whatever. You are probably wiped out regardless.
The only scenario in which the options are more interesting is as noted, very early stage companies where the exercise price is really small, or insane rocketships with an active secondary market providing real liquidity. Or, I guess when the company itself is holding liquidity events regularly (and even then it's only interesting if the FMV continues to grow up rapidly).