Corporate interests control policy through money. How is that not directly related to capitalism?
If money controls policy, then capitalism is working better than democracy. To balance it you either weaken capitalism or strengthen democracy. I think the latter is a better solution.
Even people who don’t take bribes can be gradually manipulated into holding certain views via marketing/lobbying
If you're arguing we should balance this by reducing the power differential present in money, I'm all for that. But that means providing housing, medical care, food and a dignified quality of life to everyone and democratizing work places so money accumulation becomes largely a status symbol and not an alternative pathway to political power.