The ability of bacteria to consume and destroy infrastructure is bounded by energy and resource considerations. Observe that we use wood for structures all the time, a material that can be consumed by any number of very common bacteria that we don't need to hypothesize about, yet properly cared-for wood can last hundreds of years.
True, but we didn't care for plastic the same way, because we didn't need to. Until now. It's not the end of the world, of course, but we should prepare for this problem.
