The purpose of government is to protect us from criminals.

In the absence of proper government, the strong will always take from the weak. -- Chris Hayes

Your sources are right. (True) Capitalism made democracy possible, because it gave the common man a variety of ways to earn his living, by working for others, by opening his own business, by entering into partnerships with other men, even by working in or for government. He has options and choices.

Once the means of production (Capital) is controlled by an elite, that freedom of choice is removed. The only way you can then avoid exploitation is by joining the exploiting elite, and they don't like to share.