It doesn't make any sense to only look at the birth rate in a geographically constrained area. Of course you can cherry pick a place and say the birth rate is sub-replacement. But the world wide population has more than doubled in the last 50 years. These 'developed' countries are shooting themselves in the foot with their immigration policies, not their birth rates. Over the next 50 years, the countries with the most open borders will be the countries with the strongest economies.

Why do we need replacement?

Should automation not allow less people to acomplish and care for more?

Overshooting into rapid contraction in developed countries sucks.

Better to reach equilibrium or very slow contraction. Give social and economic systems time to adapt.

The entire social safety net was designed to run on a population ponzi scheme. The old outnumbering the young presents existential threats to the current world order.

Technology is a labor multiplier. It’s invention creates efficiently and allows more production from the same work.

That is fine. Developed countries consume a disproportionate amount of resources.