I believe you are probably right. the problem is that capitalists only focus is profit. so if their profit is limited by this hypothetical non-corrupt government they will try their absolute best to make sure they get their way in the government, and since they have a lot of money they also have the power to do that.
also the ideology of endless growth for the sake of growth (how capitalism works) is literally impossible on a planet with limited recourses
And let's not forget the societal implications of celebrating and institutionalizing abject greed-is-good mentality. Capitalism inherently trends toward zero sum thinking and acting. Little wonder it always leads to something resembling fascism in the end. Some countries just haven't advanced that far yet, but that's why it is a very real threat even in what my fellow Americans idealize in democratic "socialism," a "socialism" in which parasitic capitalists still get to retain ownership of enterprise while they grow fat and rich off the work of others. This is why there has been a resurgence of ultra rightwing extremists around the world in capitalist systems.