I think the sheer amount of planets with Earth-like conditions make it outright improbable that some of the basic biochemicals such as amino acids and more complex macromolecules (proteins, membranes, etc.) and simple biological forms don't exist elsewhere.
The step that is difficult to judge imo is how likely it is that developed organisms begin collecting/harvesting and living off their environment (what pushed humans to develop past primitive tribes). This is obviously required before language and all later forms of development may occur.
In either case, I think dwelling on the possibility or trying primitive forms of contact/signaling is largely useless and effort should be placed on exploration and research in science (physics+astrophysics). Science fiction does have a significant upside in inspiring and motivating new students to enter the field, so imo discussion about aliens should be stimulated, but carefully.