1. Make contraception and abortion more readily available in the third world shit holes that are the primary cause of overpopulation, funding women's education in said shit holes and enforcing 1 child policies.
2. As for the West keep the system as rigged as it is, so that smart men will continue to not marry and breed fully knowing that the government will screw them over in case of a divorce. Also severely limit immigration. We have negative birth rates in the West and let's keep it that way.
3. Jokingly pray for corona to mutate into a super virus that wipes out half the human population, but only jokingly.
4. Wipe Africa from the map. Also a joke of course.
All of these options sound cheaper than making entire planets habitable and flying the entire human population there. We still have billions of years until the sun explodes and we can easily continue to live on this planet for a really long time if we solve our overpopulation problem.