The reason for the large number of narrations by Abu Hurayrah (may Allah be pleased with him).

The Shaykh : The hadiths of Abu Hurayrah come to approximately five or six thousand, or perhaps slightly more or less. As for the hadiths of 'Abdullah ibn 'Amr, they may reach one thousand and five hundred or so. In any case, they are less than half the number of Abu Hurayrah's hadiths. The reason, in brief, is his exertion and his contentment with the bare necessities of food, drink, and clothing. The second reason is the supplication of the Messenger (peace be upon him), which is the strongest of the reasons for this. The third reason is that he collected hadiths from the Companions. This reason is actually very clear, for we find that among the four Imams, Imam Ahmad is the one with the most hadiths. Why? Because he traveled to the scholars of hadith in the various regions of the Islamic lands and elsewhere, and he collected from them what the others did not collect. Thus, even though he was later than them, he had more hadiths than they did.
So this hadith gives us the meaning of the well-known wisdom: "Whoever strives, finds," and "By the measure of one's toil, high status is acquired." So we take from this hadith about Abu Hurayrah two things. The first of them is related to the core of the subject, which is the contentment of the Companions with a modest living and their not turning to the enjoyment of this world, even if such enjoyment is permissible. The other thing we take is that a person, through his exertion and specialization in a certain matter, excels in it and surpasses others, even if they are more advanced than him in knowledge and older than him in age.