I think you underestimate how much plastic is consumed in a lab doing experiments or analysis. I suspect it's an order of magnitude or two more than people are regularly exposed to at home or other non-industrial settings.

When I was an automation engineer at a lab, each liquid handler alone could go through several pounds of plastic pipette tips in a single day. All of that is made out of plastic and coated in a different thin layer of plastic to change the wettability of the tip. Even the glassware often comes coated in plastic and all these coatings are the thin layers most likely to create microplastics from abrasion (like the force of the pipette picking up the tip!). Throw all the packaging on top of that and there is just an insane amount of plastic.

The only place I've seen more plastic consumed is industrial and food manufacturing where everything is sprayed and resprayed with plastic coatings to reduce fouling.