I almost iterally said there are there are infinite integers. You still don't get the point, silly.
If all of them are finite, then, no matter how much or how fast are you increazing n in 1-1/10^n, because n is still finite.
Unless you can find one integer n that is not finite, then 1-1/10^n is permanently less than 0.999...
The gap is never 0
0.999... - (1-1/10) = 0.0999...
0.999... - (1-1/10^2) = 0.00999...
0.999... - (1-1/10^3) = 0.000999...
The gap is never 0, brud.