It seems to me that what Arendt problematizes is not so much that things have changed or that the world is different but, the way in which the world is different or perhaps how things have changed. As you stated, its obvious that things are different and that things change. It is simply a fact of life that nothing stays the same. We all experience such changes on a frequent and regular basis but, its not so much the frequency of the change so much as it is the nature of the change. Some things change for the better, some for the worse. In this way, I think its more an issue of the trajectory of the transformation rather than the transformation alone.
In this regard, I do think the changes Arendt is discussing have caused or have lead to a fundamental alienation in the general public. I think a key feature of alienation is that it often goes unrecognized, especially in the general public. Alienation is something we are, more often than not, unconscious of. I think it is for this reason that Hegel and Feuerbach described alienation as false consciousness. Each suggested that once alienation becomes recognized and once one becomes conscious of alienation it will be overcome. Marx did not subscribe to the idea that the totality of alienation was false consciousness. Marx suggested that alienation comes about because of material social and economic factors. Here, false consciousness can still be associated with alienation but, the recognition of alienation does nothing to alleviate it. Alienation can only be overcome through changing the material social conditions which caused it. Thus, even here the general public is not aware of its alienation because it is become so deeply and almost inherently embedded into the very functioning structures of society. It almost becomes a simple fact of life, simply the way things are. The worker is often unaware that he is alienated but, the brute fact remains that he is, according to Marx. The worker does not own the means of production. The worker does not own what his labor produces. In order to achieve or maintain his subsistence the worker is forced to sell his labor and so in effect the worker no longer even owns his own labor. There is alienation in every one of these instances but, it is often unbeknownst to the worker. It is simply the way in which he must carve out a living. The alienation has become part of the fabric of his life.
You could also liken this to the Christian notion of original sin, the fall, or human depravity. While I don’t necessarily consider myself a Christian there is something interesting in these ideas. Man is born into a condition which he cannot control and which he did not choose and because of this, one its most common features or symptoms is that man has no idea. He does not recognize his sinfulness. He is not conscious of the fact that he is “fallen” or that he is “depraved”. With this in mind, Alcoholic’s Anonymous is another useful example, in that, the first step to recovery is admitting you have a problem. Perhaps, then, you could say that alienation could be likened to a kind of cultural denial.
I think Arendt is plotting a similar course, because of specific sociological events and conditions we are alienated from the world, alienated from the Earth, alienated from each other, alienated from ourselves, and ultimately alienated from action. It is built into the very structures we are surrounded by. At the risk of becoming too nerdy I quote from the film The Matrix:
The Matrix is everywhere. It is all around us. Even now, in this very room. You can see it when you look out your window or when you turn on your television. You can feel it when you go to work… when you go to church… when you pay your taxes. It is the world that has been pulled over your eyes to blind you from the truth. … That you are a slave… Like everyone else you were born into bondage. Born into a prison that you cannot smell or taste or touch. A prison for your mind.
The Matrix is a system… Businessmen, teachers, lawyers, carpenters… these people are still a part of that system… You have to understand, most of these people are not ready to be unplugged. And many of them are so inured, so hopelessly dependent on the system, that they will fight to protect it.
If this is the case then, while our ability as a species to adapt, to embrace change, and to thrive in it has made us successful at survival it may have, in fact, done far more to systemically perpetuate and ingrain the conditions of alienation.