As the quote above shows, the brief and fleeting chance to "finish off"(direct quotation) the Italians in Libya before the DAK could be equipped and manned to combat-effectiveness was squandered away by Churchill's quixotic decision to parcel off the British armoured units to assist the Greeks.
With what?
Compass (which was never intended to capture Cyrenaica and started life as a 5 day raid ending up as a 2 month rout of the Italian 10th Army) had exhausted the forces in North Africa and as Rain has pointed out the Axis won the reinforcement race by a country mile.
Wavell later lamented that Opsec derived intel and other sources of Rommel claiming he did not have enough stuff convinced Wavell that the Axis were not going to attack before he had a chance to refit his forces in North Africa and the curb stomping of the Italians during Compass had made him too blasé regarding the Italian capability to recover as well as they did.
He understood that he had time.
Rommel was not sending this information to his superiors to catch the British out but to con his superiors into sending him more stuff
If Wavell believe that at the time - would not London think the same?
What Wavell did not have was the forces or the Logistics to advance into Western Libya even had the forces sent to Greece not been sent.
I agree and 'wish' that the Greek 'adventure' had not happened as the extra forces remaining in North Africa might very likely have prevented Sonnenblume from being as big a success as it was and result in a much lower 'high tide mark'.
However I understand why 'Churchill' (and by that I mean HMG - Winston was not a dictator) made the decision to reinforce the Greeks and involve the Yugoslavians (who were probably next after the Greeks anyway).