Capitalism is the single largest guarantor of freedom the world has ever known. It is also the ONLY system that has ensured that resources are allocated to where they are most desired (matching willingness to pay). There is no such term as "monopoly capitalism." That can not exist! A monopoly is not capitalsim, so "monopoly capitalism" is not possible.
At any rate, capitalism is dependent upon the freedom of the people to do with their resources as they wish. To ensure this freedom, suppliers must be able to sell their products at prices and under conditions that they choose. The buyer must be able to accept the situation or walk away. He may also offer new prices and conditions, but the supplier must have the choice to either accept or leave.
In capitalis, all parties get what they most value in the end. Understand that capitalism protects property rights, and thereby freedom, equally for everyone. It does not see race, gender, age, religion, or anything else. In capitalism, your stuff and your freedom is yours, not to be touched or infringed upon. It is as equal and equitable as is possible.
But, those who don't like it think it is not "fair." They think that the rights and freedoms of only some people should be protected, and that assets may be taken from some people to give to others -- those who already have what they arbitrarily determine to be large amounts should not enjoy the same freedoms that those who do not have an arbitrarily-determined amounts do. In other words, those who do not like capitalism believe that the world should operate in their own view and that they know how to use individual wealth better than the owner of the wealth does. They want to involve themselves in others' business, take their freedoms away, and tell others how their assets should be used.
There is no doubt that capitalism provides the greatest benefit for the greatest number of people.