Britain has nowhere near the capabilities it had back then it terms of logistics (ie ships taken up from trade). Moreover, they are getting rid of a huge amount of airlift: https://ukdefencejournal.org.uk/c-130-hercules-fleet-to-be-r...

Even for Falklands conflict, they barely managed to win, and that was with assistance from their friends vis-a-vis missile codes, satellite imagery, etc.