On the other hand, if you think the software industry has a hard time figuring out (at hiring time) who the high performers are... science is driven by serendipity. Nobody can predict who will find the billion dollar discovery. Not even past performance is a reliable indicator.
So it makes sense to me that the salary spread in science is relatively even. If they could reliably figure out who to dump money on, they would. On the other hand, the FAANG companies clearly believe their hiring practices can select out the high performers... and perhaps they are right? If they're paying 3-4X what everyone else does, they expect to get at least 3-4X the value.