I think boycotting has an effect. It may not be the end of the world for a game by any stretch, but it gets attention. Also polite communication on social media has more reach than people anticipate, even when coupled with the potential for lost revenue. It just runs into the brick wall of profit. If they think a mechanic will gain more profit in the long run, it's probably not going anywhere.
Then again, you have situations like Battlefront II which suffered a huge backlash over the monetization system they tried to implement and it was released on day one with that feature disabled. They revamped and improved the game quite a bit since that time without anything but the ability to buy crystals for skin packs since. I would think they are actually making a meager profit or losing money, but are scared of tarnishing the license.
Standing your ground on your convictions can have an effect.
This nonsense about games causing violence is tired and not based on reality. Humans are violent. That has never, and will never change. The sad reality is too many people have insulated themselves in society, and forgotten just what we are capable of. I think our arrogance as a species is pervasive.