This is something you'd learn in your first year at law school. If, as Trump's complaint alleges, Dominion did destroy evidence then the evidence is immediately assumed to support the opposing party's allegations.
Biden's defense would now have to prove there was no fraud as if Trump's team had certain evidence of there being such.
All the US Supreme Court has to do is declare the election spoiled in three or four swing states, and the election goes to the House.
Destruction of evidence may be the critical factor in determining whether the election was spoiled.