Fordow is widely reported to be significantly deeper than GBU-57 can penetrate (which is just 60 meters). The only way they penetrate is landing two of them in the exact same hole (think Robin Hood splitting an arrow with another arrow). Off by just a little and it winds up with it's own separate 60m hole.

CEP with GPS for our most accurate glide bombs is 5 meters. But GPS jamming is cheap and easy and the best precision we get in that case is 30 meters CEP.

GPU-57 gets its power from gravity. Reaching that 60 meter maximum penetration requires dropping the bomb from maximum elevation, but without GPS, that further increases the CEP.

With just 6 bombs, it seems unlikely that they could reliably penetrate. Actual penetration would likely require nuclear penetrators, but those also break the nuclear prohibition and open Pandora's box in places like Ukraine.

A great example of the problem is Yemen. We tried to get the Houthi to stop by dropping bunker busters on their tunnel systems and completely failed. We were forced to reach a ceasefire agreement (one that likely went up in smoke last night).