Neither capitalism nor democracy are systems that most people understand properly. They represent a point or a section along a continuum that isn't a single line, it is more in the shape of triangle. Consider government. While the US may consider itself a democracy it probably has reached the stage of an oligopoly - ruled by a few people. I am Canadian so do not have a dog in this fire but I would say that the Bernie Sanders experience is representative. He was never going to be allowed to be the "Democratic" party candidate for president. On the other side, I still remember Trump's first announcement where all the people in the audience were actors.
At the other end of the scale the "Communism" of China is an oligarchy as well ... a government run by a few people. At the third point "Theocracy" ... I imagine Iran might be an example where the government is run by a few people as well. Democracy is somewhere in the middle of this triangle where the people actually retain the power ... outside of the hands of a few people.
The same dynamic can be said of business. Who controls the wealth. In the US once again I would no longer say that it is a capitalist system. The lines of communication is owned by about 6 companies, the majority of sales is probably in the hands of 2 or 3 companies. I cannot even say what country is working under a communist system ... although possibly Belarus except its leader controls many of the reins and I think luckily he seems to be a benevolent dictator. As far as theocratic economics, I hope that the last one that we saw was in the dark ages ... where the churches tithed the population ...
So capitalism like democracy in my opinion are just islands and I cannot be positive that they exist in any population greater than about 1 million people.