That's a fair point on the components themselves. But what about the plastics involved in the production of the components?

It's turtles all the way down.

Eh, when it comes to metalworking or the production of advanced alloys, again plastics really aren't a big part of the process. I bet machinists eat fast food and use plastic straws sometimes :) but maybe that's not the point.

Space rockets just aren't prime examples of how plastics enable modern tech, of course it would be hard to find something that had zero plastic in the production chain, but food, medicine, and biology are really where the plastic shines and consumer goods are where there are lots of times where plastic is environmentally competitive to the alternatives unless your argument involves transitioning to a luddite society.