Masks are for keeping your own particles from spreading far AND for lowering the probability of virions found in the environment from entering your respiratory system.
Masks lower the probability when all other variables are held constant. If someone thinks wearing a mask grants invincibility and in turn chooses to increase their exposure to high viral load individuals or environments, they're putting themselves at risk.
Both of you may be correct. I think the person you responded to may not have been precise in their framing.
I suspect that you had N95 masks in mind when you wrote masks, which doesn’t negate the point of the person you responded to, if they had surgical masks in mind when they wrote masks. Surgical masks are far more common than N95 masks since they are cheaper and do not provide protection against viral particles for the wearer.