What is the use of personification in "Mushrooms" by Sylvia Plath?

Sylvia Plath's poem "Mushrooms" is written entirely from the perspective of the titular mushrooms, who are personified throughout. Speaking as a chorus, the mushrooms describe how they "whitely, discreetly" emerge in the night, unseen; Plath gives them such human attributes as "toes" and "noses" to create an image of the mushrooms peeking their heads above the soil to "acquire the air."
The mushrooms are "earless," "eyeless," and "voiceless," and yet they are portrayed as working in unison with their "soft fists," like an army with "hammers" and "rams." They "shoulder through holes" and "diet on water." The impression is one of a vast group, working quietly and defiantly together, "meek," "edible," and yet, above all, multitudinous: "so many of us!" This line is repeated like a chant or mantra, underlining the idea that the mushrooms' great strength is in their numbers as they "shoulder" their way through the soil under cover of night.
The final stanza of the poem, combined with the reference to the mushrooms as "meek," is an allusion to the Biblical statement that "the meek shall inherit the earth." The mushrooms, moving quietly and asking very little, and yet moving as a group, state that they will "by morning / Inherit the earth." The impression is that, while the poem personifies mushrooms, the mushrooms themselves could also be interpreted as a metaphor (or as analogous) to the meek of humankind, too, when they choose to work together.