Quantization of charge is meaningful only at the microscopic level, where the charges are of the order of a few tens or hundreds of 'e', i.e., they can be counted. Such charges appear in discrete lumps and cannot be ignored.
While at macroscopic level, we have to deal with charges of few microcoulomb whose number
n = q/e
which is nearly equal to 1013, which is very large.
At this scale, the fact that charge can increase or decrease only in units of e is not visible. The discrete nature of charge disappears and it appears to be continuous.