As much as ~88% of tested kale contained PFAS, and it's because of commercial compost. Organic kale has more PFAS than non-organic because it uses more compost rather than more synthetic fertilizer.
Does it eliminate heavy metals? PFAS? Every type of plastic? Literally every other type of contaminant that I haven't thought of? Is every batch of the end product tested thoroughly? Even if contamination is rare, is it as rare as other sources of garden soil? Why would I chance it when I know the source is dirty?
Also how do you even test something like compost properly? It is not that uniform product, so test samples could be fine, but other parts metres away could have high levels of contaminants...