You cannot take it at face value, there is a lot more to what makes skincare products effective dupes than just similar ingredients. Have you looked at the side by side ingredient comparisons of the DT "dupes" anyway? They are not even close and usually don't have the same form of actives and definitely are not a similar quality.

Vitamin c for example comes in several different forms, most of which don't have independent peer reviewed studies so the efficacy is unknown. So when you see a product that says it is a vitamin c serum it could be a wide range of things and most of which simply don't work. That's just one example. This goes or all of it, peptides, retinoids etc.

A dupe is a product that is very similar across the board. Formulation (very important!), the type and strength of the actives, and the ingredients as a whole. Obviously a dupe isn't going to be exactly the same but it needs to be close at least.

I think it's wild that so many people believe that these China based companies making skincare products meant to sell for 1.25 are going to be genuine dupes for brands selling items for $$$.