The ruling does not give the president power infinite power, just that it saves him from possible prosecution. So he can order ballots destroyed, but that doesn't mean that the ballots will get destroyed considering that people in charge of election do not work for the president, thus have no reason to listen to him (same as they do not listen to Trump). However, while before 'ordering the ballots being destroyed' was a good way of getting yourself in jail, now he is immune.Can't Biden just officially steal the elections now. He can order any ballots destroyed. He can stop the count anywhere he wants. Seems an easy win if Biden understands what's going on.
Which brings us to the main elephant in the room. He can actually order the assassination of SCOTUS and Trump, and regardless if the army/secret service/whoever listen to him, there is no ground now to prosecute him. He can actually do it in TV too. Which is almost funny.