We can use language to describe and communicate something that is close enough to reality for all practical purposes.
This statement misunderstands the relationship between language and reality. Language is not a window onto reality. No statement is closer to reality than any other. In this respect language is more like music than mathematics. For example we may feel that a certain piece of music better captures a landscape or a situation than another piece of music does. And we could discuss which piece of music fits the scene or situation better and give reasons one way or the other. Reasons that include reference to tone, melody, pace, emotion, length, circumstance of production, or whatever. But if someone was to join the conversation and insist that one piece of music was "objectively" closer to describing the reality of the scene or the situation than the other, we would immediately realise that the person has completely misunderstood the nature of music, the nature of reality, and the relation between the two.
It is similarly wrongheaded to insist that certain linguistic utterances are "close" to reality. Statements should be judged for their practical, ethical, and aesthetic qualities. Appeals to their "proximity" to reality make as much sense as measuring the metric distance between stupidity and ignorance.
Cofty it occurs to me that the problem here may in part be that you've never read about structural linguistics. You decry people who reject evolution without reading about it. Before ridiculing non-realist conceptions of language maybe you should make some time to understand the theoretical basis of the ideas your are criticising first. In particular the nature of the sign, composed of signifier and signified. Then how the relation between the two is arbitrary and (this is the poststructuralist insight) inevitably slippery and subject to deference/difference. That's what Derrida is all about, by the way, in a single sentence, on my reading anyway. Not obscurantist or empty, rather straightforward and profound.