Potentially a much greater filter is going from unicellular to multicellular life, no? If it likely took billions of years to get from unicellular to multicellular life on Earth, and only (hundreds of) millions of years to get to life that can conduct spaceflight, then perhaps microbes wouldn’t be the best way to attack this problem (I’m assuming you’re talking primarily about unicellular microbes, of course).
Where does this idea that a programming language has to be Turing complete come from? As far as I can tell from cursory searches, the most broadly understood understanding of a programming language is a formal language for directing computations on a computer. HTML does this, CSS does this, and SQL does this. Frankly even configuration languages like YAML or the spare INI file do this in the proper context.
Can these languages do everything or even most computations you would be interested in doing in a computer? Of course not. But why should the definition be restricted to languages that can do everything?
Traditionally, interns exist as a well-vetted and well-shaped supply of labor (which is very difficult to find through the traditional hiring process). The work they complete is secondary. Are companies going to stop needing good employees? Is nobody going to need to work in 40 years when all the current employees are phased out?
This works great for finished consumer goods, but bulk cargo that makes up a significant portion of both rail and truck traffic like grain, liquid products (crude oil, gasoline, vinyl chloride), ore, etc. have very specialized transports that don't work well with the existing multimodal system.