This article is talking about heating plastic in a microwave which is something a lot of people do but I suspect fewer people have unloaded skids from the back of a tractor trailer in the summer. That stuff that is at room temp on the grocery store shelve has gone through a tone of heat cool cycles before it makes it to you.
For instance, I've been using reusable shopping bags for 25 years and buy most of my food through farmers market, never touching plastic bags or packaging in the whole lifecycle. That's probably at least 10,000 fewer plastic bags. Sure there's some wasteful people that probably use that in a month, I see how people shop.
This isn't a virtue contest - it's a lifestyle commitment just like deciding not to smoke for health reasons. At scale these things have impact.
Also I know there's plastic everywhere, like my phone, clothes, computer ... I'm not a idiot. That's not the same.