Izuku Midoriya is the main protagonist of My Hero Academia and the inheritor of One For All. Its awesome power enables him not only to keep up with his peers but also to surpass them in his quest to follow All Might's example and become the next Symbol of Peace.
However, there are certain considerations that make one reconsider whether or not Midoriya was worthy of such power. By reexamining the factors around Toshinori's choice critically, we can determine whether or not the future of Japan has been placed in the correct hands.
10 Worthy: Training
Part of Midoriya's process in inheriting One For All included grueling training sessions overseen by All Might himself. He practiced tirelessly day and night, often even before Toshinori had arrived to teach him.
Deku exerted his body so intensely that he would physically collapse in front of his mentor, garnering the pro hero's concern for the young boy's safety. Regardless, he has shown the dogged determination necessary to hone his body into the shield that will protect Japan from its worst threats.
9 Unworthy: Enduring Bakugo's Abuse
During their earlier years, Kacchan was a brash, abrasive bully who surrounded himself with like-minded sycophants. He openly flaunted his power to others, discouraging their dreams while exemplifying his own. This was especially evident toward Midoriya himself.
Instead of taking a stand against this behavior, Deku overlooked it, regarding him with the same fondness of Kacchan's supporters. Considering that his actions (such as destroying a table to intimidate Midoriya) were a microcosm of potential villainy, his friend's excusal of it entails that he might not have the commitment to do what is necessary. While he would muster his nerve against Bakugo later, this was only after he had been entrusted with One For All.
8 Worthy: Heroism
The inciting incident for All Might's choice, to begin with, Midoriya has relentlessly demonstrated his heroism even when he was powerless. This was proven through his attempt to save Bakugo's life from the sludge villain, a criminal who had recently almost killed him.
Placing one's life in grave peril in spite of insurmountable odds is the hallmark of heroism, and it was a tenant Deku would continue to practice on many separate occasions going forward. Touched by his compassion and moved by his courage, most of Midoriya's decisions validated Toshinori's choice.
7 Unworthy: Superior Alternatives
Izuku Midoriya was not the only candidate that was being considered to become All Might's successor. Nighteye (a close friend to Toshinori) had adamantly encouraged him to choose Mirio, a hero whose permeation quirk would behoove One For All well and add to its stockpile of powers.
Further, Lemillion possessed the same heroic qualities that Toshinori adored in Deku. This was seen through the bullet he took for Eri, as well as the subsequent brawl with Overhaul that could have ended his life if the villain had touched him.
6 Worthy: Parallels To All Might
Though there may have been superior candidates to Deku on account of their own powers, it was proven that One For All was viable in the hands of a quirkless hero through Toshinori himself. Like Deku, the Symbol of Peace also began his journey without a unique ability of his own.
This further endeared the two to one another and strengthened a connection beyond the values they shared. Moreover, it convinced the Symbol of Peace that only heart was necessary in order to save others.
5 Unworthy: Constant Crying
The Symbol of Peace is important not just as a stalwart guardian for Japan; it is also supposed to be a friend and bulwark to the powerless. Through their strength, the innocent take comfort with the knowledge that evil has been thwarted.
However, Midoriya's hysterical crying does not suit these ends well and compromises any confidence civilians place in their heroes. Given that the wielder of One For All is held to an even greater standard than everyone else, it is particularly inexcusable.
4 Worthy: Tactical Knowledge
Deku's heart is matched only by his analytical mind. After studying his opponents' moves for a few minutes, he can determine how they'll strike next with moderate clairvoyance. This was a skill he employed against Bakugo during their first competitive training mission against one another, allowing him to stay on par with the explosive anti-hero without overusing his quirk.
It would be particularly convenient against villains who can defeat their targets with a single glance, such as Mr. Compress and Overhaul. Midoriya's combat savvy is an excellent boon that compensates for his other deficiencies.
3 Unworthy: Abandoning Eri
When Overhaul came to collect Eri and use her to power his quirk depriving bullets, Deku and Lemillion both knew of his intentions. The young girl clutched him with terrified fervor, making the Yakuza boss's intentions clear from the beginning of the encounter.
Instead of confronting this evil and saving the weak at any cost (as Midoriya often did), he relinquished Eri into Overhaul's custody. This was in spite of the fact that Mirio alone could have defeated him in an even fight, much less the two of them working together.
2 Worthy: Commitment To Eri
Despite how he had failed Eri previously, Midoriya was intent on correcting his mistake. He was instrumental to the U.A Festival which occurred shortly after, committed to making her smile for the first time (and therefore demonstrating his understanding of what it means to be the Symbol of Peace).
During this time, he was even able to catch and defeat Gentle Criminal, whose powers had been massively augmented through the love of La Brava. Were it not for his vigilance, the festival would have been ruined, and Eri's spirit may not have begun its healing journey.
1 Unworthy: Slow Learner
Deku's process of learning One For All was excruciatingly slow, and the time he needed, in order to harness it properly, had almost yielded disastrous results. This was seen through his fight against Stain, his first encounter with Shigaraki, and the perilous rumble against Muscular during the Forest Camp attack.
While it may be more difficult to manage with every host, All Might was able to master it with so little effort that he did not even know how to begin instructing Midoriya. This entails that in the hands of a different user, One For All may have been controlled more easily.