Discovering new physics doesn't move us away from a unified theory, it just means we were wrong about how much farther we have to go.

Not necessarily, because it could give a hint. It is possible to get from various higher dimensional gauge groups like SO(10) to almost the standard model. But the left over particles often couple in unfavourable ways and lead to proton decay for example.

every single article on the matter has says that it would be a step towards potentially explaining dark matter and dark energy, which would help towards a unified theory