I think in this era we are so used to thinking of a "token" as a we would a video game token, i.e, a coin. But a token is not a coin, merely a representation of something else. Mistakenly, we have applied this to mean that the tokens in YGO are in fact whatever we use to represent them (a coin, dice, backgammon peices) but in this game tokens are in fact imaginary cards generated by game effects.