Have said this for ages....
If one compares liquid/gel detergents to powders ingredient list for former is often vastly larger.
Liquid detergents (especially top shelf) are a chemical cocktail long list of ingredients often designed overcome one thing; lack of oxygen bleach.
Enzymes, surfactants, polymers, maybe heavy doses of OBAs, and other ingredients are made to do the heavy lifting of shifting stains, soils, and "freshen" laundry in absence of oxygen bleach.
This is why top shelf liquids like Tide Stain Release, Persil ProClean, Persil Gel, etc... perform well enough on stains like blood, grass, wine, etc... While often not exactly same results as a good powdered detergent with oxygen bleach (or adding that substance on its own), but often still quite good.
IMHO modern liquids are far more polluting than powders because of this vast chemical list.
It is pretty much same thing as when phosphates were removed from laundry detergents. It took addition of several other things to replace what phosphates did all by themselves.
Finally this heavy chemical cocktail IMHO goes along way in explaining why many report difficulty in some liquid detergents rinsing away cleanly.