I'm aware that if such people stop fake caring then they will stop caring altogether. Well good, stop gaming yourself to life advantages please that you shouldn't have. Of course it's harder to actually care about things compared to fake caring. It's harder to be an actually good person vs faking being good and it's probably far less rewarding for most to only be getting what they should be getting in life. Luckily most people are not that good at being fake because like you said, it still takes effort. But people who do it all their life no longer feel that effort and this is how you end up with lifelong fake people.
In general we will never get people to stop faking and lying their way to advantages in life so what decent people are left with is to develop an even harder armor that fake people can't get through with these strategies. It's sad but that's what life seems to be: You have to find people who aren't just here play and beat you like you're a videogame or for a darker analogy play you like you are an asset and they are a CIA agent.