To summarize:

• capitalism always results in the accumulation of wealth in a minority of hands through monopolies and oligopolies.
• once wealth accumulation occurs that minority will always utilize their wealth to manipulate the systems which control all our lives into their favor.
• regulation can be used to redistribute wealth, but is always going to be dismantled eventually through propaganda, lobbying, and bribery. Once dismantled, we're back at square one.
• therefore, capitalism is an irrideemable system which will always reach a failure state.

This is arguable, and honestly this exact bullet point can be made for virtually any political system, but it's most likely what OP's on about.