Agreed.
They also never intended to have 435 representatives for 350 million people. It was the Reapportionment Act of 1929 that capped the number of congresscritters at 435.
In 1929, the population of the U.S. was ~122 million. It is now almost three times that. This means that in effect, the power of each representative has tripled. Concentration of that much power provides a tremedous incentive for corruption, and this is even more so in the case of the Senate. Combine the ever-increasing ratio of citizens to representatives with the ever-increasing power and authority illegitimately claimed/seized by the government, and you have all of the ingredients for what we have today: a cabal of self-serving, corrupt, despicable, career-politician vermin in congress, all getting quite wealthy while supposedly "serving the public".