We can’t predict what other forms of life may be like, but everything we’ve seen here on Earth says that life needs totally over-the-top chemical complexity. More than that, when carbon oxidizes if forms carbon dioxide and monoxide, which are gases even at low temperatures and are (evidently) fairly easy to break apart. Here’s the point: if silicon life was going to happen anywhere, it should be happening here. If some kind of alien silicon life were to happen to drop in, it would find Earth a lot more palatable than we do. But considering how short that list is, it may be that we’ll see the first evidence of non-standard alien life in the atmospheres of exoplanets.