No, because we have no idea what the bounds are. We don't know what dissimilar life could possibly look like. If I send you to a junk yard and say "Find my old

No, because we have no idea what the bounds are. We don't know what dissimilar life could possibly look like. If I send you to a junk yard and say "Find my old microwave" can you do it? You'll probably start by looking for things that look like what you think a microwave looks like, right? But what if mine looks different? We know life is probably somewhat rare in the universe, at least compared to the raw number of planets. But we know that Earth ticks all the right boxes to generate life, despite that adversity. So we look for things like Earth because it's more likely to be productive than a blind search with no bounds.