(Your English is better than my Portuguese, so we’re switching.)
As I pointed out, consumers do have leverage under capitalism, due to competition. If one company chooses to raise prices or reduce production, others can swoop in to take advantage of this, and will be rewarded by the market for doing so. They can undercut the overpriced or fulfill underserved markets.
This happens all the time. A core goal of government is to enable this by preventing collusion. Capitalism is not perfectly self-regulating and laissez-faire capitalism cannot work, even in theory. But well-regulated capitalism can and does work; you brought up the example of Norway.
Under a command economy, all this is impossible because there is no competition. There can’t be: all means of production were confiscated by the state. If the state does not want to produce something, it will not be produced. If you don’t like it, sucks to be you because you have no power.
A single-party communist government is authoritarian. Your vote doesn’t matter. You can’t get the government to care about your needs.
In terms of human rights, Cuba is a grand failure. In terms of medical care, it is not one bit better than first-world nations with UHC systems. We don’t need to give up basic human rights just to get medicine.