It's not a 1D spectrum. You can have laissez-faire arrangements that still preclude massive concentration of capital (and thus effectively gut capitalism) without going all in on public ownership of everything. The key thing to remember is that private property rights themselves require some kind of government to maintain by using force when necessary - i.e. the existence of private property is inherently a step away from true "laissez-faire". Thus the government doesn't need to aggressively collectivize anything to avoid concentration of capital; it just needs to refuse to protect such concentrated capital.