Misleading headline right? if one person stopped eating meat it would clearly not be like taking 8 million cars off the road, if everyone on earth stopped eating meat then 8 million cars would be a drop in the ocean. So… the headline means what even you want it to mean.
They’re not saying people should stop eating meat entirely, they’re saying people should eat less i.e. swapping a burger with a bean casarole once a week or something. This is not a binary all-or-nothing situation. Every little helps, as they say.