So how to prove the so called “Russian interference” didn’t make any difference between who won and lost?
Easy. You prove it by polling the voters in the swing states and asking them their reasons for voting for Trump. Likely won’t get surprising answers, just the basics of his platform.
The Russians spent $100K on social media. Hillary literally spent 6000x that, but somehow the $100K beat her $600m? Or made more of a difference than Trump's $300m? Puh-leeze. I'm sure the KGB (and the Democratic Party) will claim that they were key players, but that's the same as the CIA claiming credit for Allende's fall. Pinochet was just completing one check box out of probably hundreds and would have gone ahead with his coup with or without CIA buy-in. If he hadn't gotten all his ducks lined up properly, the coup would have failed just like the Turkish coup and countless others (including many CIA-sponsored covert ops) have over the years.