The Mosaic Law prescribed extracting a literal number out of the entire nation of dedicated Jews for the purpose of ministering in a specific assignment.
The numbers "7" and "7" in the vision Joseph interpreted for Pharaoh during the years of plenty and the years of famine were literal even though the cows and grain were symbolic.
The numbers "3" and "3" were literal in the vision Joseph interpreted for the baker and the cupbearer even though the cups and the baskets were figurative.
The number of beasts in Daniel were sometimes literal and sometimes figurative depending on the context. "There are four beasts" was interpreted by the angel as "four kingdoms" and it was literal, including the "king of Greece" that the angel named.
In Joseph's dream with the sun moon and 11 stars bowing down to him, the number "11" was literal and fulfilled when his 11 brothers bowed down to him in Egypt.
Thus the idea that the number "144,000" must be figurative is based on a selective reading of the text that does not take into account the larger context and understanding of the scriptures, namely, the entire Bible.