Nothing in the word "first" indicates that it corresponds to "one". The same for "second". Those words are not numerals, "first" is a superlative adjective, while "second" is an active participle. They are perceived as ordinal numerals only because English does not have ordinal numerals for the 2 initial positions of a sequence and "first" and "second" are used instead of the missing ordinal numerals.

The abbreviations "1st" and "2nd" are very recent and they cannot be used as an argument that there is a long tradition of correspondence between "first" and "one".

Like I have said, the correct argument based on English is that the position after the second is called "third", which is derived from "three", and the next position is called "fourth" from "4", so extrapolating backwards that sequence results in decrementing "3", which gives a correspondence between "2" and "second", and decrementing the number once more gives a correspondence between "1" and "first".

This is the exact reasoning that has lead to the abbreviations "1st" and "2nd", which have no relationship with the pronunciation or the meaning of the abbreviated words, which mean "closest to the front" and "the following", meanings that are unrelated to any numbers.