If you over 60, as I am, you remember a time when "made in Japan" meant cheap and shoddy, and anything made of plastic had to be treated carefully lest it would break. Nowadays, they are building airliners out of plastic. Things change, sometimes for the better, sometimes for the worse. Manufactured items tend to get cheaper, but sometimes they get better at the same time, as has happened to watches.
One of my favorite examples is flatware. When I was a kid, good flatware was Sterling silver. It was very beautiful, but tarnished and conducted heat like crazy. Now it's all stainless. If SS was invented 2000 years ago, no one would have ever made flatware out of silver.
And if John Browning had today's plastics to work with, he would have used it.