I used think that I have too many dishes, but then I can across a list in a 1919 book, and realized (at least by the standards of a hundred years ago), that I may not own enough dishes.
With regard to table equipment, the number of individual dishes is controlled by the size of the family, and the kind of service desired. Most housewives would choose dainty service and good style, and would prefer to have convenient dishes in adequate number and appropriate silver, even if less expensive china , and silver and glass is chosen. For such a standard, which is strongly recommended, buy twice as many of all individual dishes, glasses, and silver, as the number in the family. This makes possible entertaining with much less worry and work, and relieves one of the feeling of not having enough. It is certainly a reasonable standard to choose china, glass, and silver which is not expensive to replace and is, therefore, not a source of anxiety to the housewife.
Source: Housewifery by L. Ray Balderston (1919)