Supposedly nothing eats plastic, but apparently we have found a bacterium, Ideonella sakaiensis, that does. Now has far as I know there are bacteria that digest hydrocarbons, and that includes plastics. However the old plastic eating bacteria were anaerobic. That is, unable to handle an oxygenated environment. I. sakaiensis is an aerobic bacterium, one evolved to handle oxygen as part of the course of business. And the thing to remember about bacteria is that they are rather profligate when it comes to sharing their genetics.
What is going on here is known as "lateral transfer", and it means that a species of bacterium with the genes for a trait will pass it on to other types of bacteria, and those genes will be expressed. That is what appears to have happened here, with an anaerobic bacterium transferring the gene for digesting plastics to a population of I. sakaiensis, who in turn have started eating plastic successfully.
Then we find out about this, and thinking it a solution to our problem started encouraging this behavior and giving Ideonella sakaiensis the opportunity to prosper and spread. The organism is already in the wild, just really hasn't had a good chance to spread beyond where it is most often found. But keep in mind that just as they got the ability from an anaerobic bacterium, so they could pass it on to other aerobic bacteria, and they in tun could "infect" our supply of bottles and shirts meaning that your boxers and socks could start to rot much as cotton and wool clothing does.
And won't that be embarrassing?
Now consider Trisha, a young lady of about 20 at the local beach for socializing and displaying her form in a one piece suit. Then a six year old girl announces to everyone in hearing range that Trisha is "flashing". That is, there are now holes in her swimsuit, a couple of them in just the wrong places. Made aware of this some people, boys for the most part, make rude comments, while others, adults for the most part, check out what they are wearing and discover that they too are now on display.
Oh the consternation. Oh the dithering and running around. Oh the sun burn in sensitive places and the run on clothing made of natural fibers.
Now for the young children finding themselves au natural is just a lark. Though you can expect their parents and the other adults will get rather protective. With the older folks a lot would get embarrassed, but not all. You can also expect there to be a run on cotton, linen, and hemp at the lower end, with the better off switching to silk. And expect laundry detergents of variable efficacy to appear on the market.
And keep in mind just how much plastic we use in our lives. Basins and tubs, cutlery, intravenous lines. tons of stuff. How do we replace them? We'll likely come up with treatments to sort of hinder the rotting, but that will add to the cost of plastics, making a polyethylene shirt something of a luxury item. Clothing factories sending out packages of sludge that were once button down shirts. And suits etc made of specially treated plastics that require expensive care. You may have to pay thousands for a polyester double knit. And then you have glass jars and bottles making a return, with all the problems that come with them. Medical supplies will just have to become reusable, and plastic tubing a prize to be treasured.
Life is adaptable, which means we have to be adaptable too.