The American experiment was a very good effort to produce a representative government that was a limited democratic system. It evolved over 200 years becoming both more and less democratic. Technically most of the population was included in the vote but based on the assumption that they could be blocked culturally and socially while maintaining the democratic pretense.
Those seeds sprouted the tree of misogyny, racism, and oligarchy under which we struggle to live. For the elite, white males things work very well as they maintained functional authoritarian control. Unfortunately that rotted the roots and shifting winds of change have drastically changed the environment.
Representatives were needed when there was no other way of seeing what people thought and wanted. As you noted the party structure effectively monetized the power and influence of the representatives. The representatives primarily represent those who pay them. Their salaries from the citizens represent only a minimum token payment. In an extreme predatory capitalist system only money really talks. It can be no other way.
We now live in constant and continuous contact with all others on this planet (very nearly true right now). We have access to vast and specialized information. We have access to AI agents that we can control and monitor information while providing detailed analysis independent of anyone else. Why do we need salesmen acting as representatives who’s interests are not ours?
We don’t use 18th century medical systems, why do we use failing, 18th century governmental systems? These systems were good in their day but are totally inadequate now.