Not really, USD is still the defacto currency of the world market. We have huge economic power over sanctions, banking etc.
Although that is true, the days, of its dominance, is coming, to an end. You must be well-aware that the US has printed at least 10 trillion dollars this year alone. Anyone, who knows basic economics realizes the more you print, the more the value of that currency goes down. The rest of the World knows the US dollar is nearing toilet paper status and are quietly moving away, so not to create a panic that crashes the global economy. However, rest assured, the other major nations, of the planet, are getting ready, for the global economic reset everyone is talking about.
This is not how you become a powerful nation. Isolationism has never worked that I know of.
It depends, what version of isolationism you are referring to. In order, for China, to become the powerhouse that it is today; it had been an isolationist country, for many years, after the market reforms Deng Xiaopeng instituted. It has been only, in the last decade or so that China began adopting a more international foreign policy.
Geopolitical isolationism and trade isolationism are not always inclusive to each other.
Safety from other nations, No one wants to go to war with us, or mess with our citizens.
You don't need the military machine that the US empire currently has, if your goal is to deter foreign invasion. Having a nuclear deterrent will make any nation think twice before invading. Unlike what US imperial propaganda tries to indoctrinate, the DPRK's main goal, in having a nuclear weapon, is to deter an invasion, from the US empire. They already have the bomb and notice that they have not used it, like so many warmongers were saying they would. South Korea know this too and you don't see them panicking because they know why they got it, in the first place.
We get minerals, labor, and other advantages and other benefits of being powerful and a world leader. We also get buyers of our goods and trade. If we isolate we can only use what we have in our borders. This lessens what we can do. The world is a large place, lets take advantage of that. Our technology leads the world and others pay us goods or money for our services and things. The global economy is a good thing.
First, what you are talking about is imperial exploitation that no ones likes. Second, you may be confusing geopolitical for economic isolationism. Third, the global economy also leads to the importing, of unwanted immigrants, as well as their diseases. Think about that.
I hope you are wrong, if china takes over and we become weak our outlook on the future of my old age and my future children will be bleak.
America's future is not bleak, if it returns, to the policies that made it a strong republic. Furthermore, there is no nation stupid enough, to take over the country and adopt the domestic problems that the US currently has.