>>538297952
Reminds me of the monster girl problem in MGQ where monster girls would eliminate the human population because human women literally cannot compete.
The solution is to either strongly incentivize or outright force the procreation of the endangered species (in this case, pure mobians). There are over 8 billion humans in this world, so it would take a long ass time for pure humans to dwindle down, likewise, halflings would be considered a step up over being pure human anyway.