Reduction of population won't hurt either provided is not too drastic. If population were reduced about 10-20% in 20 or 30 years, that won't be so bad.

Sure, economy and taxes would need to adapt to the change. Older people would need care and there won't be so many people to care for them, so governments would need to step. But a 10% less population could mean less pressure on limited resources.

At some point people who choose to not have children is making a responsible choice. If they feel they can't provide properly or that the world won't have enough resources, they aren't completelly wrong. After all, there are people having more children than they can afford and take care of. One compensate the other.