What if people convince governments of their nations to make Bitcoin as a legal currency or what if we agree to give tax on our bitcoin income? Will government then make Bitcoin a legal currency.
It is possible, but it will need to remove complete anonymity from the owners of bitcoin, and this is contrary to the structure of bitcoin. In order to pay taxes, you need to understand who pays them and to whom. At the moment, this is almost impossible, since bitcoin is actively used in the darknet and anonymity is the main factor why people are willing to tolerate crazy commissions and waiting time for transactions.