Seeing as Dave is canonically known as Thunder Warden, and we have some idea of him as a giant mech (i.e. game files listing him as such with a "hatch" on his belly area and a "lens" on his head, I have a few ideas on what his use could be. It feels safe to assume he is a creation of someone, possibly Jonas, possibly someone or something else entirely from the rust world. I have seen discussions on Dave used as a communication device, but considering his name I theorize he is a means of collection. The spines sticking out of him remind me of the lightning rod design in the game. We have yet to understand just how the prima materia (ref. Schematic D) was discovered. There is possibility conduction is used, and Dave is a giant means of collecting the electricity needed to create this essence. A few things lead me against this theory, such as the strong possibility Dave is not created from someone here but rather a creation from the Rust world, and the knowledge that Jonas locked himself up in his alchemy lab for months (ref. Reflection Part 4) which means he would not have recurring access to lightning to create the prima materia. He could have already had a large amount of it at that time and was running experiments with it, but I'm not sure on the likelihood of him not running out. This fact also points me to the idea that Dave is used for something within the Rust world itself. I wonder what kind of person/creature would create him and why. What might they need a giant moving lightning rod for? Dave has been on my mind a lot lately...
