Theoretically possible. Bitcoin networks have been able to handle a lot more transactions per second than the current processing volume. But it is not yet fully mature enough to scale up to the main credit card network. Work to improve the current cap is ongoing and future demand is also very clear. From the beginning, every aspect of bitcoin networks are maturing, optimization and specialization, this process will continue in the next few years. As traffic increases, more bitcoin users may use lightweight clients, while full network nodes may become more specialized services.
As far as we know, bitcoin is not defined by the legislature as illegal currency in most jurisdictions. However, some jurisdictions (such as Argentina and Russia) strictly restrict or ban foreign currencies. Other administrative jurisdictions (such as Thailand) may restrict the granting of licenses to certain entities, such as bitcoin trading platforms. Our country is the bitcoin is defined as a kind of Internet products, therefore, bitcoin digital currency to replace the dollar as the encryption is a thing very distant in the global circulation.