I think you missed the quote monjaro posted which I responded to "According to the generalized uncertainty principle, the Planck length is in principle, within a factor of order unity, the shortest measurable length - and no improvements in measurement instruments could change that."
i.e. Planck lengths is the shortest measurable length and thus you can't measure anything of smaller length, and so the smallest length any object can have is the Planck length.
i.e. Planck lengths is the shortest measurable length and thus you can't measure anything of smaller length, and so the smallest length any object can have is the Planck length.