If nothing else, Singapore showed that even the British Empire, with in 1941/2, still the largest navy in the World, could not seriously defend even a vital asset (or allied Commonwealth nation), on the other side of the planet, when the British Isles were not in a secure situation and her forces were already fully engaged on several fronts.
So 25 years later, when maintaining a viable force 'East Of Suez', including a carrier group at all times, was competing for resources with the forces defending the nation in Cold War, largely by forward defence in Germany, for the RN
, a large ASW force for the Atlantic, with an expanded sub force as the Capitol ships for this role, as well as a large tactical RAF, the priority was clear.
Running the nuclear deterrent was about to get much cheaper though, as the V-Bombers gave way to Polaris. That system impacted the rest of the RN
really only in manpower, since the UK got an incredible deal on the missiles.
The loss of foreign exchange paying for 'East Of Suez' could no longer be tolerated either.
In this, thoughts of the Fall Of Singapore must have loomed large.
Though the Indonesian Confrontation was one of the must successful wars the UK and Commonwealth ever fought, to deter further escalation from basically a counter insurgency jungle war, to something bigger, the UK had to re-inforce forces in the Far East. Including with some V-Bombers, conventionally armed as well as nuclear.
Had the large, recently Soviet re-equipped Indonesian forces stepped up, including attacking Singapore, the UK/Commonwealth forces would have required still more re-inforcements.
Do-able, but a strain, though US intervention would have been likely, even as they were heavily committed in Vietnam, this however might well have slowed their response and limited the forces they deployed.
But, it was more likely that any major military confrontation for the UK, would be much more directly within the Cold War context.
So defence of the UK would be the priority again, from trying to keep the sea lanes open, to air defence of the British Isles and the major one, helping to prevent the USSR
ever reaching the English Channel.
It was too close a call last time around.