you aren’t taking seriously the hypothetical world in which 1 − 0.999… isn’t zero
In this (math) world it is zero only because for every nonzero positive epsilon, you can pick a FINITE number of 9s, such that 1-0.999999...99999 (a FINITE number of 9s) is already SMALLER than that epsilon.
For EVERY real number greater than zero, you have a FINITE number of 9s, such that this difference is smaller.
Therefore the difference cannot by a number greater then 0.
In this (math) world it is zero only because for every nonzero positive epsilon, you can pick a FINITE number of 9s, such that 1-0.999999...99999 (a FINITE number of 9s) is already SMALLER than that epsilon.
For EVERY real number greater than zero, you have a FINITE number of 9s, such that this difference is smaller.
Therefore the difference cannot by a number greater then 0.