Seeing your title, it caught my attention almost immediately... Supporting you stand, I think graphene actually had the potential to power the future, but then just as you have rightly pointed out here:

while the production or making of graphene in little quantities for laboratory use could be cost friendly, it is really very expensive to mass produce it. This ultimately limits its use in products or researches which require it's use in large quantities.

Getting this miracle material in large quantities might take months, years and even decades before its fully achieved.

A quite lengthy but yet educative science article. @gidionline