The Royal Navy is dependent on Americans to complete the other ships to protect the British carrier. So if Argentina retakes the Falklands and USA said no, the Brits won’t be able to retake the island unless they want the aircraft carrier to sail by itself thousands of miles all exposed to the Falklands.
Argentina's military has degraded to a point where they aren't a threat to anyone, much less the Falklands.
Argentina’s military is a joke, its no threat to the Falklands and won’t be for some time. There are plans in the works to increase the size of the escort fleet so that by the 2030s there will be up to 30 frigates and destroyers instead of the current 19, so Argentina, if it ever does become a threat, will be facing a larger navy than it is now.
Even as things stand, the Type 45 destroyer is more capable than every Type 42 destroyer that was sent with the task force, and this taskforce has two of them along with two type 23 anti-submarine frigates, an Astute class submarine and fleet support vessels. It will also be joined by escort ships from other nations making it a formidable force against any potential enemy.
The budget increase is going to sea the RN become a potent force again.