They don’t use the mechanisms, they exploit them. Capitalism is at its core about simple value exchange: it takes x man hours to extract a material, y man hours to process them and z man hours to build a product from them. The cost if the good should be (x + y + z) multiplied by a reasonable profit.

Instead, we have businesses paying significantly less than the time cost for the work, while charging significantly more. This abuse and exploitation is the root of the problem that people blame on capitalism - but capitalism isn’t the cause of the problem, the cause is the people who exploit.

Similarly, with communism everything is supposed to be fairly distributed. However abusive people exploit the system by establishing themselves as the ones who decide how things should be distributed, and violently silence anyone who disagrees.

Any alternative system must focus on the people problem in order to be an effective solution, not the perceived problem with current systems.