Marxism does not have a “binary class system,” and modern times are not distinct from Marx’s time when it comes to class dynamics.

Well, in the Manifesto, he argues that the complex medieval system will collapse into a twofold system (hence binary) of haves and have-nots, those who own stuff and those who have nothing to sell but their labor. Arguably he adds the lumpenproletariat as a third class (in contrast to the "reserve army" of temporarily unemployed who still belong to the working class) but it's a small, marginalized group. He predicts that the middle class, while still prominent in his time, will disappear. Some modern Marxists will add other classes due to their relation to wage labor, like feminist Marxists who view unpaid care workers (like housewives) as a distinct class or anti-colonialists applying the class system to the relation of the global south and the global north. While I agree with both groups on many things, I wouldn't use the terminology of "class" in this context but that's just terminology. I wouldn't agree nor actively disagree on that if that makes sense.

Other Marxists will double down on the twofold distinction, insisting that it's only about either investing money or being paid; and therefore the national manager of a multi-national company has the same class interest as the factory workers, the middle management, the office workers who may or may not – to use Graeber's terminology – have a bullshit job. And that's a lens that's not really helpful. First, it does not agitate well to tell people their boss is basically on the same level because this doesn't feel right (and I would argue it isn't). If the power structure stays the same, what even changes? I looked it up and my CEO made €2.1 Mio last year. Reinvest or not, this is exorbitant more than I ever will. He isn't CEO anymore, his successor is a woman, another win for feminism (\s). the only stakeholder is the state and that's basically the way you want things to be, right?

What Marx had in mind was a factory worker and if he talks about higher workers, he's talking about foremen in direct contact with the manual worker, not a manager. I would argue that the stratification happened all over again. Modern work environment resembles feudalism much closer than Marx' idea of two classes (not necessarily in the inheritance aspect but in many others).

As for socialist states not withering away, why would they be able to without the eradication of class globally?

Sounds like an excuse without an expiry date. If an anarchist experiment is smashed by a Bolshevik state, it's because they never would suggest anyway. If said Bolshevik states doesn't bring us nearer to a stateless society, it's because of the other states.

Bakunin was wrong, in the end.

(This is from a previous comment I haven't responded to)

Just to make sure you know what I'm referring to when I say some of what he said aged well:

So the result is: guidance of the great majority of the people by a privileged minority. But this minority, say the Marxists, will consist of workers. Certainly, with your permission, of former workers, who however, as soon as they have become representatives or governors of the people, cease to be workers and look down on the whole common workers' world from the height of the state. They will no longer represent the people, but themselves and their pretensions to people's government. Anyone who can doubt this knows nothing of the nature of men.

source

It reads as a comment after the fall of the Soviet Union but it's from the 1870s. I even like Marx' reaction. I wish more Marxists today would have kept to this side of Marx.