In past years the damages to reputations could be a lot more local and shorter duration when the false charges are refuted with facts. Local people would know the full story and would be less inclined to hold something like this against a person once charges were proven false. The accuser would take the reputational hit.
Today you make charges like this online on social media and there is no way to scrub that from the record. Those allegations will persist like an incurable disease and will be accessible to anyone locally or internationally who searches for info about the accused. That reputational hit will persist on the accused for their lifetime and into their children's lifetime. Penalties for false allegations like this should be very harsh.
For the reasons you laid out, the people who consciously and falsely accuses someone of a crime should be charged with the same crime, but double the penalty (for they tried to both ruin a life, and deceive/abuse the system). Obviously malice needs to be proven in this case too.