Darwin first speculated about the primordial soup as the origin of live.
Discovered is the wrong word. The concept of a primordial soup being the place where Abiogenesis occurred is a speculative theory.
There is absolutely no empirical evidence to support this theory.
The Miller Urey experiments found some amino acid necessary for life. These experiments were formulated on the theory that the early atmosphere was a reducing mixture of gases. Current evidence indicates that the early atmosphere was an oxidizing atmosphere.
The odds of forming even the simplest functioning proteins by random chance in a warm pond are astronomically small to the point of being impossible.
The primordial soup is a philosophical position that life came about by random natural causes. It is not an empirical discovery.