I rejected the deal because I got even more elsewhere. My framing still stands. In a case when only one employer has the information, sure they’re better served by offering me more money. But in an environment where all of them have the information, this no longer is a problem. At a system level, this is a problem for employees.
The story you seem to have told is they just wasted time low-balling you because they didn't have enough information to offer a competitive salary. You weren't ever going to settle for $250k, they didn't have enough leverage and they lacked the information to identify that. I'm not sure how you're seeing this story as one where more information to Meta leads to them offering you a lower salary. It seems like you'd have rejected them regardless unless they went higher.
All the employers knowing that you'd have "taken the job even if they offered $200K" seems to be completely useless to them. They're locked in an auction and the market price for your time is nowhere near $200k.
No, such a discovery wouldn't be possible, because nobody would pay that amount to someone who was willing to accept $200K.
> They're locked in an auction and the market price for your time is nowhere near $200k.
There is no magical market price that exists outside the market dynamics. When bidders know that one's current salary is $150K, their willingness to offer higher salaries will diminish accordingly.