Thanks for this really insightful comment @praguepainter!! That's a lot to respond, but even without reading the whole post in detail you hit the nail on the head all along the way! This post is actually from a draft of a paper I started a while back but pulled out because of another post I saw which focused on the "contradiction of being anticapitalist". Interestingly, everything you mention (except your paragraph on Amazon and declining consumer purchasing power) is in this draft haha. Nearly reaching mind reading level there! :)

These guys have figured out how to make money out of air and their machine is perfected.
-> exactly! The added twist in this story is that it has been decoupled from debt, which has been thrown on the backs of citizens. This is something Colin Crouch, who I reference above, covers in detail in The Strange Non-Death of Neoliberalism.

don't brands and "nihilist cool" mostly exist on a superficial plane of appearances
-> Yes I completely agree. This is not something I detail above but leave implicit as I detail it more in my draft. Rather, I return to the notion of mimesis to explain it. But they are indeed superficial constructs since they are more about identification with the system (where even rebellion becomes part of the system and therefore a valid form of identification) rather than actual values and identities which have any substance about the good or moral life. Rather, they are the illusion that capitalism provides us the liberty to choose what life is good for us, when in fact they are just variations of the same life provided by capitalism. This is deeply linked to my understanding of signifiers.

Signifiers: The power of capitalism, liberalism and the state is that they rely on a constellation of signifiers which emerged and work together hand-in-hand to justify the nihilistic and 'baseless' psychology under capitalism. So capitalism is not baseless and does indeed have its own signifiers! It is grounded in the Enlightenment concept of human as a purely rational, autonomous and unified Self. This + Kantian dignity provides the basis for liberalism. Capitalism comes as the economic system which best enables individuals to exercise this autonomy (translated as self-interest) in a rational manner. The Westphalian state enshrines these concepts in law and provides a means of enforcing compliance with the system.

Where does the solution start? New signifiers! :) So worry not, you are not old-fashioned or conservative! Or if talking about signifiers and that we need them is old-fashioned, then the rear-guard has become the avant-guard ;)

we desperately need a reality-based global economy that responds to the human needs of the global citizenry
-> I see a transition to energy-based valuation as a key to transitioning to a new economic system. Firstly, this should introduce the real cost, both material and human, of what we produce. I hope it will also reorient production towards more useful ends as we realise the waste of much of what we do economically. Also, it will make the producer-consumer loop much smaller, ideally bringing the two into direct contact (agroecology etc.). Secondly, it enshrines the passage to the ecological paradigm we need to shift to and will provide the basis for understanding it. Can it create new signifiers? Partly (in theory at least..) since it should serve to underline the interconnected nature of much of what we do (complexity theory etc.).

Excuse the short responses to your different points (that said I've beat my record for longest comment haha). Nonetheless, you have motivated me to cover each one in a post! Looking forward to discussing these topics more with you! :)