Plastic is the evil created by World War II, which also gave us some lifesaving medicines. During WWII, there was a steep rise in demand for metals to manufacture military hardware. To reduce the demand, plastic was introduced to replace metal wherever possible. So, plastic was deliberately made hard not to degrade and last long. Until WWII is over, the plastic was not available for civilian use. To get rid of the huge piles of raw plastic accumulated by the military, the US Congress permitred the use of plastic for civilian use and released several tons of plastic. The Congress did not seek the opinion of environmentalists before passing the law to release plastic for civilian use. Immediately, industry took advantage of this as people were excited to own plastic goods. When I was in school in the 1960s, Surf detergent company used to give one plastic bucket free for the purchase of two big surf packets. Soon, households were full of plastic buckets, replacing the metal containers wherever possible.
It takes decades or centuries for plastic to degrade in landfills. Every plastic toothbrush we have used since childhood is there intact somewhere in the landfills or soil. It is not difficult to introduce molecules that break apart due to sunlight and thus make plastic disintegrate. But then, the smaller pieces do not disappear. They stay intact in soil forever, causing more problems.
That said, plastic really helped us in many ways. For example, please look at the pharmacies full of plastic bottles, as well as the hospitals with plastic tunings, lines, gadgets, etc. It could cost a lot of money to use alternate materials to replace plastic in healthcare. Can we imagine a stethoscope without plastic tubing? Until the year 2000, we were using glassware in research labs. The high-quality glass used in labs is expensive and heavy. It is sold by weight. A 3 liter Pyrex glass container used to cost $600. And they can break during use. Washing and drying glassware to reuse was expensive, consuming tons of water and detergents plus energy and labor. Sterilizing glassware is another issue. So, a major chunk of research budget used to go for glassware. But slowly, plastic was introduced into research labs. In about 15 years, almost all glassware in research labs was replaced by single use plasticware from China. It was clean, available in sterile conditions also. Moving to plastics saved us substantial amount of research money.
So, plastic is like eating French Onion Soup. It is messy to eat, using both spoon and fork alrernatively. But it is so delicious, we do not give up eating. BTW, our profession is plastic-dependent. Our iPhone and Tesla are useless without plastic.