“American help in 1982 has been grossly exaggerated.”
Thatcher thought it crucial and decisive, as I recall.
I don’t think you’d not have won, it just would have been uglier.
Still, you’re right that Argentina has no chance today - they cannot mount an amphibious landing, assuming they even had troops with fortitude to fight.
Unfortunately, Pinochet isn't around this time, to help the Brits.