Taking the Falklands is not the same as holding them

Could Argentina seize the Falkland Islands in a modern conflict?

Only at severe cost, and Argentina would be unlikely to hold them against a British response built around current carriers, F-35s, and anti-submarine forces.

Mount Pleasant is a strongly defended position, and an assault could succeed only if Argentina accepted substantial losses. Britain's Queen Elizabeth-class carriers, F-35s, and anti-submarine helicopters change the balance from 1982. A British retaking effort would likely use a different method from the original campaign. Landing on the islands and sustaining control of them remain separate military problems.