I'm not an expert and 409A valuations are not a joke but the current rules around 409A valuations are there to prevent people valuing them too low to reduce taxes, not too high because - why would you?
Some scenarios:
A company's "real" fair market value is $50 and this is also what they report to the IRS. They issue options with a strike price of $60, which are $10 out-of-the-money. This is an allowed transaction.
B) The FMV reported to the IRS is $40 but the "real" FMV is $50. Options are issued with a strike price of $50. The IRS thinks that these options are $10 out of the money and therefore allowed, but they should actually have been taxed more-or-less as income.
C) The FMV reported to the IRS is $60 but the "real" FMV is $50. Options are issued with a strike price of $65. The IRS is happy that these options are out of the money, which they really are. If the IRS audits and challenges the valuation, they may come up with a price closer to $50 but that only means that too much tax might have been paid which they're not going to be too upset about. Meanwhile, for the purposes of reporting compensation of their prospective H1B staff member, the barely out of the money options look a lot better than they should.
The IRS is set up to look for B, no-one looks out for C.