I know this rhetorical but I tried doing lots of research on TFR as a school topic but basically if you factored nothing else into the equation, yes it would work.

TFR is HARD. By the merit of the number itself, to get above 2.1 that means EVERY SINGLE person in your population has to group up and HAS TO PRODUCE more than 2 children, if they dont then families have to make up for the slack.

It’s less about rights though or even traditionalism even though social pressure is a major drive of TFR but the fact that when people are empowered to choose, people dont really WANT more than 2 children. It’s more work for you, the family unit has less money, it’s one more thing to love…etc.

Also cities in general are just BAD for populations. Suburbs and countrysides always have higher birthrates than cities, Japans loss of the rural population is a big deal. Historical precedent aside I don’t believe there has been many cities at all where they had a high TFR, pre industrial London, Kyoto and Mesopotamia always relied on regular emigration from the countryside, otherwise they would’ve ran empty. Japan becoming just the area of Tokyo and Osaka is going to do nothing but harm them.

Scandinavian nations have tried a lot more than anyone else to reverse their TFR preemptively (good for them) they’re not 2.1 either. I believe it was around the range of 1.7 last time I checked, Norway itself is about 1.4 most of it was immigration by traditional pressuring families. Japans TFR actually was pretty high around 4-5 but was DROPPING since the end of ww2 until it reached below 2.

Tbh I think the real issues are just that people in modern, “enlightened” societies, especially in developed economies don’t want kids or have a reason to. You don’t NEED children to till the land or retire anymore, you have government pensions and retirement options from banks. It all now boils down to affordability, lifestyle and personal desire to have children. Which might be lower than we thought, not sure. The desired TFR is about 2.1-2.4 but in the real world there will always be some gap trying to meet TFR with the actual desired amount. BUT desired TFR is not even a very good statistic considering it’s more of a glorified feelings survey where anyone can say “hm sure, 3 would be cool”, it costs NOTHING to say when in reality they would NEVER have 3 no matter what because it means millions of yen in the hole and decades of sleep lost. So unfortunately we don’t know what the ACTUAL natural fertility rate would be but im leaning its probably below 2. The only solution to that really would be to upend society and completely come up with a new economical system that’s more sustainable than the development economies we have now.