Tank and armored vehicles were main difference between WW2 and WW1, and major technological breakthrough that make us think about WW1 as static and WW2 as mobile war(fare). This was recognized during WW2 itself, and there was a large focus on destroying or disabling enemy armored formations. Aircraft, as another technical novelty, was considered as an tank buster. However, there were difficulties.
At the beginning of the war, aircraft were armed with classical unguided bombs of various weight. Tanks were small, relatively well armored and often moving targets. Therefore, aerial attacks on them were not easy. They were usually performed from shallower or steeper dive, and even with larger bombs had to be within dozen or so meters from the target to have an effect. Considering poor bomb-sights (or no bomb sights at all) on most fighters and fighter-bombers this required considerable precision. To rectify this, anti-tank bomblets (like this Soviet PTAB bomb) were developed. Working principle was simple, plane would drop them over an area hoping that some of them would land directly on enemy tanks and destroy or disable them with their relatively small but powerful shaped charge. This worked best against formations, but attacking plane had to fly low (thus exposing itself to anti-aircraft artillery), otherwise dispersion of the bomblets was high. Next, we have unguided rockets (like HVAR), on the surface potentially devastating against tanks, but in reality to imprecise to be effective. Again, pilot would need to go really close, but at that range it would be more effective to simply use bombs. Finally, higher-caliber guns were mounted on some aircraft (like Hurricane Mk IV with 40 mm Vickers S guns) . Again, theoretically these would be good anti-tank weapons. In reality, recoil and dispersion were high, so pilot again had to go really close into the teeth of anti-aircraft defense. Plus, such tank busting aircraft were usually heavier and slower then their regular counterparts, making them better target both for AAA and fighters. While Hurricane IV pilots did claim 47 tanks destroyed (both German and Italian) in North Africa, this is very doubtful as tank kills by aircraft were enormously inflated in WW2.
So what did Desert Air Force achieve ? Role of the aircraft in North Africa was primarily to disrupt logistic chain . Attacking ships and aircraft that brought supply to Axis in Northern Africa left Rommel both without fuel and without replacement vehicles (and some other stuff) . And again, supply dumps were targeted, as well as convoys consisting of soft-skinned trucks and other vehicles. As a result, Axis were not able to withdraw their mechanized forces from El Alamein. Instead, they were obliged to defend this position in set-piece battle of attrition which favored Allies. Most of the surviving German and Italian tanks were destroyed by their crews when they run out of fuel or ammunition, and this goes for other vehicles.