Of course we are still using euros & dollars, because up to now, no other currency could overcome the bootstrapping problem of network effects, to be useful. Bitcoin is changing that. Thats why we are all here, on the bitcoin forum.
I am here to tell you that you are an idiot. I'm in the educational sector. It is my calling.
You are kind of missing the period when paper currencies replaced very well bootstrapped metallic ones. How did that happen?
In stages. Metallic coin --> privately issued metallic-backed paper --> central bank issued metallic-backed paper --> central bank issued pseudo-backed paper --> pure fiat. And that series was of course
assisted by government coercion. Our task is much harder. We are trying to bootstrap a new currency that can overcome both the network effects advantage enjoyed by the current system AND the government coercion that's attempting to prop that system up. And for a long time those two hurdles in combination seemed insurmountable. But Bitcoin might just be the revolutionary technology powerful enough for the job. Time will tell.