Was Hannibal a Failure?

I think Hannibal would have considered himself a failure, but he would probably have also blamed others, especially the Carthaginian government for not giving him more material support.
Should Hannibal have besieged Rome immediately after his decisive victory at Cannae? That has been the subject of debate for millennia. I can see his reasoning for deciding not to do it, however. He expected the Romans to sue for peace, something that any other nation would do after such a resounding defeat. He didn’t anticipate their dogged resistance. The Roman Senate declared it a crime even to mention the word “peace.”
Hannibal was not prepared for a siege. He had no siege equipment and he had an army of 40,000 which he would have had to keep fed in hostile territory for the months it would have taken to starve Rome out. Hannibal had conducted a successful siege at Saguntum in Spain, but it had taken nine months and he had had 100,000 troops at his command and all of the resources of southern Spain at his disposal.
Hannibal though it a better idea to make alliances with as many cities and tribes of southern Italy as possible and isolate Rome. In this he was initially very successful. The cities of Capua, Tarentum, Croton, Metapontum, Locri, Arpi and others allied with him as did the Atalani, the Catalini, the Hirpini, some of the Apulians, the Samnites except for the Pentrians,, the Bruttians, the Lucanians and the Surrentinians. After the Battle of Cannae, where the Romans lost 55,000 Roman and allied troops, it was quite reasonable that all of these cities and tribes believed that they were joining the winning side.
So how could something that had seemed like a wrap have gone so terribly wrong? How was it even possible for the Romans to recover from such a resounding defeat?
After Cannae, the Romans recognized that Quintus Fabius Maximus had been right all along. It was not productive to fight Hannibal on his own terms. He was a genius on the battlefield. So under the leadership of Fabius, the war became one of attrition. The Romans largely avoided confronting Hannibal in the field and concentrated instead on punishing and subduing his allies. They still had two legions of troops that had survived Cannae and perhaps two more that had been under the command of Marcus Claudius Marcellus who hadn’t fought at Cannae. They scraped the bottom of the barrel to get troops, recruiting boys barely out of the toga praetexta and even recruited ten thousand slaves on the promise of freedom if they performed well. By 206 B.C. they had clawed back nearly all of the territory Hannibal had controlled after Cannae and had Hannibal bottled up in a small area of Bruttium.
So how might Hannibal have won this war? I think he would have been far more successful if he had stayed in Spain and let the Romans come to him. He would not have lost half of his 70,000 troops in the arduous trek across the Alps. He would have had 100,000 troops at his command and all the resources of southern Spain at his disposal. He would have utterly demolished any legions the Romans sent against him. The Romans would probably have kept trying and kept being defeated until they realized their efforts were futile. Then Hannibal could have easily taken Corsica and Sardinia and perhaps Sicily back from the Romans. If he were still of a mind to destroy Rome he could have built a fleet, made a treaty one of the Magna Graecia cities and used their port to invade Italy. The war would have ended with the destruction or Rome or a treaty on Carthaginian terms.