As always with most things in our capitalist society, it’s better for shareholders if general population injests microplastics than for them to spend money on products to prevent it. Capitalism only spends money on things that bring profit, not to make a world a better place. If while making that profit the world becomes a better place, that’s a marketing win.
Plant-based filter removes up to 99.9% of microplastics from water (newatlas.com)