back when the bottle were glass there were very many problems. The glass would end up on the ground. People would step on broken glass. It would end up on the highway. People would get flat tires. People would get serious injuries cutting themselves. It involved a lot of trips to the hospital. Glass bottles in automobiles that crashed would cause serious injuries to the people in the vehicles. Glass used to collect berries would break and cut a child's hand.
It was a very good idea to not use glass anymore. But one needs to have the correct kind of plastic.