The distasteful concept of overpopulation only comes about because the majority of people are not given the opportunity, or any reward for contributing positively.
Potentially, all humans, and all living things add value. There can never be too many.
With the right system of rewarding all people for their individual value added to the planet, and society, where that value is evaluated by the majority, no-one will be a burden, or excess to requirements.
Add solar power as the source of wealth in that new system, to fund all rewards, and things will be very different.