stop with the false dichotomy bullshit. you can not consume lead and not consume artificial sweetners at the same time and of course lead is worse.
to your broscience comment - first all of the artificial sweetners taste terrible. second sucralose and others like it are an industrial produced chemical and an ingredient that makes a food an ultra processed food. there are some studies that suggest artificial sweetners can increase inflammation (consistent with other industrially produced chemicals), impact insulin sensitivity, impact intestinal lining and therefore the gut biome, etc. now there are studies to refute that as well, but unsettled science isn't broscience, particularly when the product under study is a for profit man made chemical (not questioning science but I am recognizing where and how studies are funded which often leads to unsettled science). Furthermore, if you are taking an approach of trying to be extra healthy and focus on as much of a natural foods diet as possible, then there's no reason to consider sucralose and other artificial sweeteners as benign especially with natural sweeteners like monk fruit are available.
And that applies to the protein powder to begin with, natural food sources are much better and the only reason to partake in whey powder to begin with is because it's pretty difficult for many (myself included) to get the protein intake that current science suggests we consume. but frankly with the lead disclosure it may very well be best to suck it up and eat more lean protein and leave the powders and shakes behind.