Bitcoin might have been designed with some other purposes in mind. It could also be co-opted by a government. For instance, I suspect that subsidized energy for bitcoin mining represents a government monetary policy, but I don't know the extent of the influence or its real purpose.

Moreover, like a technology, people will use money if it's useful to them. For instance people in countries with "bad" money will often use it for daily expenses, but move the bulk of their assets into instruments based on the currencies of the US, Europe, etc.