The point of the senate was to give proportionally larger representation to less populous states and make congress more conservative (harder to pass drastic changes). Then as now, there were major disagreements whether those are good or bad things.
The US government was designed by a wealthy, powerful, few who were trying to strike a balance between favoring democracy and being scared that would mean the loss of some of their power. The result is a strange mix of entrenched over-representation of the privileged few (wealthy, white, male, etc) while lauding the ideas of equality and democracy.
