Boku No Hero Academia - One For All - What Does It Mean To "Stockpile" Strength?

One For All is the Quirk of the #1 strongest hero All Might, and said to be the rival of the Quirk All For One, however, the description of it is fairly vague, being that it is said to just be the combination of two Quirks. One which allows the user to pass the Quirk to someone else, and the other which allows the user to "Stockpile" strength. However if we look at the definition of stockpile:

Definition of "Stockpile"

A large accumulated stock of goods or materials, especially one held in reserve for use at a time of shortage or other emergency.

It really just means "to have a large amount." Is this really the limit of the power Sensei's brother and his successors believed capable of beating All For One? Maybe if they kept passing it on so there were 100 All Might's running around, but as it is and has been with only 1 successor at a time (that we know of) this seems a little much to ask of such a basic, and not overly rare, power.

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During the Sports Festival Arc, in his fight against Hitoshi Shinsou, Midoriya feels and sees the presence of (presumably) the past inheritors of One For All.



Could this be a glimpse into the future possibilities of One For All? Perhaps inheriting the Quirks of others, without stealing, truly the opposite of All For One, similar to how he's inheriting the will of his predecessors?