Stop responding is a fools argument. The game has changed a lot since the days of your average internet trolls because the line between internet and reality has become increasingly blurred.

For example, I don't use Facebook. But my parents do. I've had to talk with them on more than one occasion because they would get caught reading objectively wrong things spread on Facebook by bots. Thankfully my parents trust me enough that I can be an authority on those sorts of things, but it's not something I can simply ignore. If I were to let it fester, eventually it could turn into things like 'vaccines contain brainwashing bleach' or 'the government wants to take away your spleen' levels of nonsense.

At a certain point it's a good idea to stop platforming people like anti-vaxxers but it's also irresponsible to say it's possible to just ignore it.