Nonfictional researchers plan for their engineered organisms to stay in the lab, in tubes, and, eventually, in industrial processes. Such organisms might even already exist on the outside, having evolved the old-fashioned way. Remember, the world has bacteria that eat lots of other things we love: metal, bread, cheese, our own skin. And we’re all still here, nibbling bread and cheese, sitting on metal chairs. Given an eons-long head start, the microbes have not yet managed to take over. So, unless nature gets remarkably better remarkably fast (it took something like 50 years to make the inefficient version of PETase), or a rogue actor stages a coup, no bitsy beasts will be gutting your Walmart kayak anytime soon.