That's not really what's being said. We know there's more to find; we know there's problems with our current understanding; we know we haven't found "the bottom".

The problem is, we've found what looks like a bottom, and all the looking we do for cracks in it, or knocking on it to find hollow spots, or hitting it really hard to try and bust through, just keeps coming back with everything being unbroken, solid, and unyielding.

It's not self-congratulation; it's frustration.

No. The nightmare here is physicists knowing the Standard Model can't possibly be the bottom, but lacking clues about where to find stairs.

This comment itself might be the "real" gold, if in a 100 years, we actually make no material advances in experimental physics and the state of the art remains. I would bet that it's quite likely, unless somehow we achieve communist utopia and the world economies combine to fund a solar system size accelerator.