This is sort of hand-waving away the problem of locality. Star Trek transporter or not, there is only a finite space on which certain things can be easily produced. And this production space is embedded in time as well as space.
So you must also add to this hypothetical world that the production space(s) must be large enough to accommodate each person's self-production at an arbitrary point in time (to avoid task switching/ allocation friction). I.e. the iron mine must be large enough to accommodate everyone on earth at the same time.