I don't have statistics, but I believe the more common scenario is that the company gets acquired, and the return on investment is not the 10x or 1000x or 1000000x the VCs hoped for, so they recoup their original investment. Leaving the engineers with options worth nothing.
I view liquidation preferences as VCs offloading risk to employees because they can.
Just like the “declare strategic bankruptcy a few months before graduation” doesn’t happen much because student loans aren’t discharged in bankruptcy.
Both moves would “break the game” in a very similar way and so are blocked.
This is absolutely correct and it SPEAKS VOLUMES about the reality of the startup world, even apart from this discussion on liquidation preferences. I'd recommend anyone looking at working for a startup to consider the above and then consider the fact that as an employee they'd be in an even worse position than those founders before turning down that far more lucrative offer from BigTechCo.