And the US has every right to do whatever they want. Why? Because they had the capability. Let Russia and China revolt about it, but that's all they can do. No actions are really made about the reserve currency of the world after all. Also, Bitcoin? as a replacement? Nope. Well, not at least in the next few years. Plus, with how some countries are fully against Bitcoin, welp, I doubt it's development as such would be an easy road.
US would probably dominate till the next few decades, and Bitcoin would only have the chance to develop through those decades, which is difficult, very much so. Especially if while Bitcoin develops, the US dollar also develops right? There's also the issue of it being accepted by the world. A currency being forced bt the top isn't really a currency that could be accepted after all.
1) Mining: requires expensive technology and a level of technical training to improve work.
I have no idea how this became attractive in your opinion.