Capitalist propaganda has done a good job of equating itself to market trade so thoroughly that many people can't even imagine markets existing outside of capitalism, and they think absence of capitalism means nobody buys anything from anyone else.

In a socialist system he would still be allowed to sell his own work and profit from his labor. Your point makes no sense

How does not stop people from selling and buying.

You know "capitalism" is just a word used to describe things, right...

Not sure I understand your point, sorry.