After a while living in an echo chamber of yes-men, you start to believe your own bullshit.
Also, valuations are so nebulous and ungrounded in reality at this point. Who is to say what anything is worth. You put something out there and someone is willing to pay billions for it, who are you to say that isn't the right value. There are a lot of problems to pin on Adam, I don't think the valuation is one of them.