IMO, the plastic double meniscus and triplet lenses in most plastic-lensed Polaroids are well out of the "toy camera" lens -- they were, in fact, the lenses that convinced the world (back in the 1970s) that "optical resin" was neither a joke nor an oxymoron. Even in the 1960s, the plastic-lens pack-film cameras were capable of quite decent snapshots, at least on what amounted to 3x4 contact prints.
There have been, however, a goodly number of plastic cameras down through the years that took excellent images, and some have been labeled as "toy" cameras after the fact -- so if you want to call a One Step a "toy" camera, be my guest...