I think bitcoin will become a global currency only when we make aware everyone from this currency, and in our business we accept only bitcoin and not any other currency .
Awareness isn't quite a big deal. Actually with the current of numbers of bitcoin users it's enough to become this crypto a global currency. But still it isn't considered as a global currency? Because in most of the cases, bitcoin used to get profits. Yes, an investment and that isn't the role of a global currency.
1st. if you want to be globally known, you need to have an awareness campaign, so bitcoin awareness is needed to make it globaly known and thus for the global adoption.
2nd USD is also considered as investment or any other currency due to it's inflation and deflation thing, that is why FOREX is there. even the stock exchange. So how can you say investment isn't role of a global currency?
Pretty much little by little Bitcoin is Becoming Global currency since any one from the world can use Bitcoin and Buy stuff online or pay bills thru 3rd party.
Awareness campaign would cost something right? So who would pay for that? That is one problem.
USD is an investment yes. It is money itself and also investment. I know some people who cant move their USD to their local currency because they are waiting for it to increase. Every cent counts on them.