If you can't articulate them, or have no basis for determining what about individual cultures make the world 'better' rather than 'worse' then your initial statement is meaningless.
If you can, then you establish a basis for determining whether some cultures make the world mo' better than others, whether or not you choose to do so.
How about something simple, like the Arab introduction of the use of the "zero" to mathematics ?
I would say that made the world better ...