You're not wrong in that. Where you are wrong, however, lies in believing that a few upstart young legislators will be able to get the big money (and with it the bought and sold influence) out of politics. The ONLY way to do successfully do that is to reduce and/or remove what government has to sell, which is power, and that's simply not going to happen. Why do you think FaceBook is running ads calling for more internet regulation? Simple, FB has the money to buy influence and shape any new legislation to be very favorable for themselves and to screw competitors. Why do you think Quid Pro Joe's son got that extremely lucrative job? Simple, he had access to the VP's office and all the power that went with it. Even those upstart, idealistic youngsters are going to, before long, become the establishment they profess to oppose. They will become, in your terms, sellouts but will be impossible to remove due to their longevity in office.
No, you need a bunch of TRUMP!s to show up on the scene with both the balls and the clout to take on the entrenched powers that be and actually push them back, and you need more than one. You need several in the House, the Senate, and of course, the White House. Of course, you could go to term limits and deny the voters the chance to elect the people they want to elect.