There's a source of microplastics people don't see.
You ever notice how your lint trap doesn't quite catch all of the lint, and your dryer hose slowly fills with lint? What is lint from synthetic clothing made out of? And where does it go?
Washing and returning glass bottles (even though the trips are made anyway) uses more energy than making virgin plastic so it isn't the win you might expect.
In fact I buy less stuff than many people I know. It is how my family can live on just one income (though I do make far more than average), and save a fair bit. However that is my life choices, I avoid judging others with different lives.
Don't see why we can't just go back to that.