Are you exaggerating or do you have actual sources? I did some searching around and can’t verify your claims.
The choice to reject new information just because something has been studied a lot is a very anti-science take.
People should understand aspartame, and understand sugar, as much as they can and make their own choices for their health.
Neither Coke nor Diet Coke are nutritious. Whether one or the other is a risk is specific to a person, and aspartame as well as other sweeteners aren’t fully understood in terms of risk.
I think these kind of simplistic statements serve to stoke fears around food than actually help people understand them. Added / excess sugar is associated to health risks but ultimately people need to understand their own health as individuals.
Here’s a Healthline article (by no means an authority but still fairly informative) to help expand.