It's pretty clear you do understand what they mean by "capitalism", then.

At this point in many countries the institutions of power have been captured by the owners of capital and many of the issues facing modern society are a direct result of this.

People will always act in their best interest and along the interests of their class, and no class is more class conscious than the capital owning class. In the US, this informs policy, which is generally geared at making the capital owning class more money at the expense of everyone else.

I don't see any other reason for us to have such excess and have it all seemingly go to waste. We could solve world hunger right now with our advances in technology and [corporate] central planning but that would never happen under this economic system.

> We could solve world hunger right now with our advances in technology and [corporate] central planning

Thera are not even a correlation, but straight cause‑and‑effect relation between practice of "our advances in technology and [corporate] central planning" and the hunger

Well if what they meant was specifically this nuanced thing, they should have said that nuanced thing, and not said "capitalism". Many other people who also say "capitalism" could be more expressive by saying exactly what they mean, instead of using the word, which is little more than a grumbling noise.