B Bob, BN was not essential in winning the Falklands War, it made it 'easier'/quicker but assets would have been moved by other SH ... eventually!
F3WMB, I would suggest that without the Harrier we would have had no aircraft to protect the Fleet, as experience proved other AD methods were not capable of protecting the Fleet adequately.
AFAIK the Government decided UK conventional Carriers were going regardless and the RN were lucky to slip the Harrier through the system.
Your point re personnel is spot on, but we would have made the most of any platform that had been purchased and there were a number of other possibilities.
I think many posters may be naming their favorite aircraft rather than answering the OPs thread title.