No, birth control is an option. Make it available to anyone who asks for it (permanent kinds included). China has a rather more authoritarian approach. I prefer voluntary methods (without incentives). It isn't a complete solution because: 1) there will always be variation in skills among people even if the population is reduced. 2) With few enough people (extreme case) mass production of goods is not necessary. 3) I think there's an old argument that with robots providing everything, eventually there is no incentive for people to even become smart enough to maintain them and the system falls into disrepair. I'm not sure when or what equilibrium might be reached. I am sure that less people would help the problem and does not require planetary emigration. It is a viable partial solution. It is not a complete solution.