Unlike the Sauron in The Lord of the Rings, our Sauron has the Ring firmly in his possession and rules over all accordingly.
Our quest to destroy the Ring and create something better in its place failed a few centuries back. We now dwell in the consequences of that failure. Once again, our Sauron has the Ring in his possession and wields it accordingly:
One Ring to rule them all, One Ring to find them, One Ring to bring them all, and in the darkness bind them. In the Land of Mordor where the Shadows lie.
We don't have to worry much about destroying the Ring physically/materially. Sauron is taking care of that himself.
Our task involves destroying the Ring and its associated power spiritually within ourselves, which entails moving beyond all of Suaron's Ring machinations and recognizing that our only hope lies in our creative spiritual activity outwith the Ring-System, in Sauron not finding, bringing, and binding us in the darkness spiritually.
And since the material is just a subset of the spiritual, our spiritual activity does and will affect the Ring System, but not in the way Sauron expects or foresees.
You often use the term quietism here. I don't know why. I reject quietism, but its opposite is not "Hey, let's stay politically active in Sauron's totalitarian one-ring System so he can find us, bind us in the darkness, and keep us in the Land of Mordor where the shadows lie!"
"only a conviction that I want to leave my children and grandchildren a world in which they are free to be something like me. Not replicas, but showing a family resemblance."
Forget abstractions like "world." Focus on your children and grandchildren as beings you love. That is the world.
Motivate them to recognize that their freedom does not depend on Sauron and his Ring System.
Understand that you can't give your children or grandchildren a free world -- that must be won by each individual. Understand that without that freedom, no individual can pursue the good.
Understand that their future will inevitably differ from yours regardless of what you do -- because agency, motivation, causality, etc.
Have faith that God will always leave open paths to goodness, beauty, truth, and ultimately, salvation regardless of what Sauron does or doesn't do.
Sauron lost the Ring once. Who is to say he cannot lose it again?