Back then, plastics were considered the pinnacle of human innovation. By mixing polymers, humans have created a material that couldn't be seen anywhere else. Alas, humans aren't really equipped for those sort of innovation at the time and the result was a catastophic mess. A hundred years from now, many of the plastic waste would still clog waterways. I'm glad that recent innovation surrounding biodegradable plastics have been embraced. Let's hope that plastic becomes obsolete before humanity does.
It's a hope yes, so I hopefully hope that we won't become plastified before plastic gets obsolete. ... and that they don't produce some even more harmful material.