"Compare that to the following:

A: Capitalism doesn't require violence in order to function.
B: But literally every capitalist economy is underwritten by violence.
A: Yes, but pure capitalism doesn't require violence.

See?"

Which capitalist economy was "underwritten" with violence? You realize "underwrite" means "accept liability for", right? Where does violence come into consensual exchanges of capital among private property owners? If I rake someone's lawn for a glass of lemonade, who was the victim of violence?