Trading and markets are not the problem. Unbounded accumulation of capital is. Capitalism is actually
anti-free-trade and anti-free-markets because it creates a positive feedback loop where the more capital you have, the more economic rent you can extract from others, which can then be used to grow the capital. At the end of that loop is a degenerate market dominated by a single monopoly or a few oligopolies, not free in any meaningful sense.
Therefore, if society wants free trade and free markets, it needs to prevent this. And the easiest way to do so is by making unbounded capital accumulation impossible, by refusing to acknowledge it as legitimate property right past a certain point, and thus withholding society's protections for it. It doesn't mean that all property rights are gone.