Ultimately, every asset class, including money, is something people can choose to migrate to or away from according to their ability to trade it for another asset. And with a money, the promise is that you can exchange it for anything else; so if everyone has more money they have more agency to trade for goods and services of all types. The problem is twofold:
1. Without an intervention you get the sharp shock of exuberance and crash; this behavior defined 19th century economies and eventually the 1930's depression and its following war that motivated adoption of Keynesian interventionist policy. Economic theory in the academy today is routinely defined in "post-war" terms, as if the preceding centuries did not exist, outside of researchers who make it their speciality.
2. With interventions, you introduce some form of market distortion no matter which way you frame it. The original Keynesian experiment approached a crisis in the late 1960's, because it pushed for fiscal interventions(government spending) which soaked up demand that would have gone to other sectors; when you do this, the other sectors experience rising prices, resulting in the stagflation that defined the 1970's. The transition into the Reagan era(a gradual series of shifts that mostly occurred in the 70's, marked finally with Paul Volker's new Fed policy) marked the shift towards a "lean and mean" neoliberalist approach with rising inequality, as you note: instead of trying to expand the economy through fiscal policy, we began the monetary-focused regime that has lasted up until now, of tuning inflation rates through fiat policy with a focus on allowing capital to redeploy itself wherever it saw fit. This era created a pretty harsh recession, but it did motivate growth again. But inequality eventually drags down an economy by a similar mechanism of "borrowing demand" from consumers and giving it over to capital, and since the strategy is to stimulate with low interest rates as necessary, and regulatory capture has favored keeping the good times a-flowing, we've used it more and more since 2008, until we've ended up in another stagflation crisis marked by our successively larger and larger asset bubbles. Eventually the chickens come home to roost and the resulting asset speculation carries over into consumer prices.
And that's the kind of crisis that existentially threatens the dollar, because if even consumer staples are holding their value better, there is no reason to hold a dollar position, and therefore to trade and be taxed in it. The bet we are making by holding dollars is not really that this can be fixed in any permanent way, but that it can at least hold out for another cycle of growth. And that leads to the headline: pushing up unemployment is one way to suppress dollar demand. It's more palatable than having a war to reallocate assets, at least.