Aspartame isn't just widely consumed, it's practically universally consumed. If it was carcinogenic in humans, wouldn't there be obvious epidemiological evidence to back that up?
Regardless, where did you get the idea it's "practically universally" consumed?
Taking soda for example, people typically either do or don't drink diet soda, and in much of the beverage chillers I've seen "diet" is stocked in the minority (with limited regional variation). Bear in mind diet itself is fractured into aspartame and stevia and various others.
Similarly, aspartame or sorbitol or other artificial sweeteners are presented as an option for most hot drinks, alongside sugar - in my experience it's the sugar constantly being replaced on the table.
Looking at packaged foods, I can find few products containing it, and again, packaged foods are only a subsection of all foods out there.
Also there are those among us who consume predominantly (in many cases only) fresh vegetables, fruit, grains, legumes etc.
Look at India, China, Africa, and everywhere in between - this is well over half the worlds population and while many are exposed to at least a small selection of packaged foods, few can afford them, and many simply have no interest.
Just a cursory glance and very rough estimate showed 6000 metric tonnes of Nutrasweet produced in 2014. Divided into a population of 7.8 billion gives each person less than a gram per year.
Aside from the fact that like all products a chunk of that will go back to landfill unsold, there simply isn't nearly enough for it to be universally consumed.