I recently watched a doc on "paco pacos" in Brasil, rudimentary vehicles made of recycled metal bits welded together in the shape of a truck, while the engine are recycled diesel water pumps.
https://www.youtube.com/watch?v=O6ovT41nc3I (in German, but the pictures speak for themselves).
Diesel engines are ubiquitous and well understood, anyone with the knowledge can repair one if not build one, with nothing but rusted spares. Electric engines on the other hand seem complex, needing dense circuit boards with tiny components and obscure microchips. Or is there an electric equivalent as easy to make, easy to maintain, and working in terrible conditions?