Why is radicalism bad? A viewpoint being closer or fartger from the median viewpoint in society has no bearing on its correctness or incorrectness. At one point, heliocentrism was radical, most people used to see the Earth as the center of the solar system. At one point, abolition of slavery was radical. Radicalism isn't bad in and of itself.

As for the system you describe, it's just not possible. In a capitalist economy, ie one where the large firms and key industries are privately owned, through ownership of the economic base the bourgeoisie has control of the political arms of society, the state. As such, regulation will only be with the explicit consent and approval of the bourgeoisie, including at the expense of lesser capitalists and of course the working class. The system cannot genuinely be tweaked into working better, even the Nordic countries are decaying, and they already depend on imperialism to function.

What works is socialism, ie public ownership of the large firms and key industries, with the working class in control. Rather than the ruthless nature of monopolized markets, we should work towards collectivizing and planning the economy. Humanity can become the masters of its destiny, rather than profit. In time, this results in gradual sublimation of all property, until all of production is collectivized and classes cease to exist, ie communism.

This is the way in my opinion. Proper anti-monopoly laws, solid progressive taxation, public (state) control of the "necessities" such as electricity and water, a working social security system, free education and healthcare while maintaining private medical practicioners and schools as an co-existing paid alternative.