I keep seeing birth rates discourse end in "and I guess the long term solution is exowombs" and, ignoring questions of how long such a technology will take to make, that is not the issue with birth rates. The carrying is not the issue, it's the raising and paying for children that's the stop gap. If it became possible to 3D print babies, that would not change the population growth rate more than a little.
If we could somehow solve the care and investment issue—say, by the discovery of magical brownies who loooove taking care of kids and gladly work for a saucer of milk—then the actual production of kids would not be hard. Pregnancy is a pain but not a bad tradeoff, if the kid isn't also a huge time and money suck. And if society still can't make enough kids, surrogacy is a known thing that could be publicly funded.
Also, we are at the tail end of the largest population boom in human history. The human population has quadrupled since in the last century and octupled in the last two centuries, due to increased availability of resources, reduced infant mortality, etc.
For the past 200 years, there have been significantly more people being born than dying. People have naturally accepted this as the status quo because it's been happening for 10+ generations, but in the grand scheme of things it is abnormal. At some point the birth rate is going to go back to replacement level and the population is going to level off because infinite growth isn't sustainable.
Yes there are going to be some practical issues with an aging population as that transition occurs, but that is inevitable and far more easy to deal with than trying to artificially prop up birth rates.
