Long term Argies are still Argies. They can’t build a functioning economy that could support an actual, capable military, and even if they did, by that point they’d have a lot more to lose by attempting to invade the islands. They’d end up being sanctioned and isolated by Britain’s allies, of which the UK has more and more powerful ones than they have and their economy would collapse.
One of the reasons why they gave up combat jets is because Britain makes a lot of the components used in western jets and they refused to supply any if the contracts were aimed at Argentina, and Britain’s aerospace industry is likely to be crucial to making western military components long into the future, and Argentina is not.
The strategic situation of Argentina is likely not going to improve relative to the UK at any point in the foreseeable future, certainly not in our lifetimes.
You're right about the Argies. However, the British will not always have a first world military. Their welfare state is depriving the military of necessary resources. They may find it too expensive to maintain their two aircraft carriers that will be activated in the next couple of years.