Right, exactly. A runaway bacterium that ate medical equipment, electronic equipment, industrial equipment, vehicles, food packaging... that would be a Bad Thing. It would mean an end to much of the modern world.

I'm reminded of a reddit discussion on how awful it would be if a coronal mass ejection event destroyed all electronics on Earth. They were lamenting how tragic the loss of Netflix would be given the current lock-down, oblivious to that it would presumably result in society collapsing, with millions or billions dying in the ensuing famine.

On the one hand I understand what you are saying, but on the other hand we've only had good plastics for a couple decades.

That's not relevant. We know it's possible to build a society with no plastics, but the question is how much harm it would do if plastics suddenly started to rapidly decay.

We've only had widespread electronics for a handful of decades, but if we lost it overnight, we'd be unable to produce and distribute food at the necessary scale. Restoring the global economy wouldn't even be on the horizon, we'd be too busy dying of famine.

We've only had the internal combustion engine for a handful of decades, but if we lost it overnight we'd be similarly ruined.

If the bacteria only slowly ate plastics, we wouldn't be doomed, it would just make things more costly, as with way rust and rot.

Bacteria fail to eat our organic wooden houses.

Sure they do, it's a major repair bill for many people. If we wind up with critical infrastructure that was previously stable randomly rotting, it will likely disrupt our current uptime rates, require expensive preventative measures and repairs, and in the end limit access to services due to the added costs. The dangers of hidden rot to electrical lines in buildings is one of the scariest possibilities.

Thats because the wood is treated with lots of chemicals. We would need to start treating plastics with these chemicals, creating potentially toxic plastics, which is not a good thing because it is very hard to test chemicals for toxicity and much of our food is stored in plastics.

Most of the wood used in house construction is not treated with anything. Only the stuff that touches soil, foundations, or is exposed to elements is. Unless you use real wood siding, that’ll be less than 5% of all lumber used. It doesnt decay, because it’s kept dry, and microorganisms arent very good at decomposing dry wood.

What's your point? We're talking about a hypothetical.