Lobbying is a fundamentally stable thing. As you observed, the economic incentives to do it are strong. And lobbying is a very general thing. Truly blatant bribery is illegal, but there are many, many ways that someone with money can help a politician and communicate what they want in return. It's hard to imagine closing that off without massive collateral damage.

Hollywood, on the other hand, is vulnerable. They're a middleman in a world that doesn't like middlemen. If we destroy them once, they won't come back.