Hello, you're actually correct about this problem. To mitigate this, we've adjusted the fertility rate to OECD standards (instead of a global value) that correlates better with the rest of our simulation parameters that are very western-centric (for now, because we will be having mods that will change this ;)
What this means for your city is that the population replacement depends more on immigration, (rather than families having children) and immigration also depends also on affordability gate. So depending on the scale of your city you could see a cascading effect more true to real life economies: aging population that is not getting replaced, producing empty flats, producing more supply and better prices.
At the same time, the ever-rising prices and affordability crises can still happen, and actually, we do want it to happen as this is also a real world scenario. But it was totally off-balance.
We are still observing the problem and getting feedback from players doing different city builds so this is something that we will continue to improve upon.
Yes, there will be market intervention tools. I'm actually mega excited about this feature but I don't want to spoil the surprise 🙃