Huh? Everyone I've ever known who had significant options knew exactly what they were worth.

I knew someone who changed their bash prompt to (price * unvested count / days left). He said at the time it was the only thing that kept him from quitting or punching his manager.

Long ago companies only bothered issuing options when the stock was illiquid; certainly my startup share options never had a meaningful market value from founding to acquisition.

Publicly-quoted companies issuing options is just a weird form of deferred bonus with a favourable tax treatment.

Well, they also come with the hope that they'll increase in value prior to vesting. But, yes, RSUs in public companies are certainly more like getting bonuses that vest over time than a stock market lottery ticket.

How do they know the price unless the company has IPO'd already?

The particular case I mentioned with the bash prompt happened at Netscape, his tenure straddled the IPO.