Pickling is not the same as fermentation. In pickling the change is caused by an acidic brine, while fermentation is done by microbes. Most pickled foods are best not eaten in large quantities; use them for garnishes.
I make a brined pickle, the salt limits the types of microbes present. The bacteria make lactic acid which does the 'pickling'. But I agree, most commercial 'pickling' is done with acetic acid (vinegar) and is definately not the same as a ferment.