That's like saying that if everything is physical, then nothing is. "Everything," by which we mean many things, is political in the sense that it has political

That's like saying that if everything is physical, then nothing is. "Everything," by which we mean many things, is political in the sense that it has political aspects that should be recognised, but those aspects are very different from one thing to another. Political means pertaining to the distribution of power and resources in a society. But what kind of power/resources, which society and what form of distribution vary greatly. That many things have a colour doesn't mean the concept of colour is meaningless, nor that it draws its meaning from things that don't have a colour, because colour is an aspect with many hues. In short, "everything is political" means learning to look at the political aspects of things. The goal is not to distinguish between the political and apolitical, but between the many different shades of the political.