i think one of the most integral parts of correctly-applied marxism is understanding that the masses make history, and that the masses are rational: that the masses act and think in service of their material interests, wherever they lie in the multifaceted world of class contradictions. that means to accept the fact that, were you truly able to live in another's shoes you would think and act exactly like they do, having experienced the same experiences and totality of material interests.
this applies to all the people you're complaining about: of course non-americans would complain about the actions of the most successful and exploitative empire, and the global hegemon for decades. even within the global north non-americans get the short end of the stick, let alone the more exploitative relationship between the US and the global south. it makes sense that these people would be frustrated for this reason
but, this also applies to americans as well: of course revolutionary politics, theory and organization would be the weakest in the state in which people on the whole have the most to lose from upending the global status quo. this is complicated by the settler-colonial nature of the US, meaning that in a sense there is both internal and external imperialism, but i think most can agree that external imperialism is primary given the lack of revolutionary movement.
the correct marxist analysis accepts the validity of both sides, and synthesizes them. if history is any guide (which as marxists it definitely should be), then imperialism is the primary class contradiction globally, socialist revolutions are more likely (and perhaps only initially possible) in countries in which capital and the bourgeoisie is less developed, the proletariat's anti-bourgeois class interests are aligned with anti-imperialism class interests, and countries in which imperialist class contradictions are particularly acute. non-socialist, anti-imperialist revolutions are still historically progressive.
for the most part, the material conditions in the US are the exact opposite of this, so anyone expecting revolution to occur within the US is anti-historical. anyone attributing its actions, the complacency of its inhabitants, or the backwards nature of its theory to a unique "evil" is not a marxist: the masses are just acting and thinking in accordance with their material interests.
i do think as the world becomes more legitimately multipolar the imperialist nature of internal american relations represents a relatively unique opportunity for revolutionary change, compared to europe for example. however, the vestiges of american hegemony would need to dissipate first: dollar hegemony, global military hegemony, etc., and we're just not there yet.
in the meantime, instead of action for action's sake, i think the best thing people can do within the imperial core and america specifically is to become disciplined, expert communists. if we truly think socialism is scientific then it can only come to be via the same expertise and academic rigor within the natural sciences. learn how to study, study, and study with others. use that expertise to write, edit and publish theory to advance scientific socialism within the imperial core. without revolutionary theory there can be no revolutionary movement.