That depends on the reasons behind why the birth rate is below the replacement rate. If it's because potential parents feel financial or other insecurity that causes them to not have children, or have fewer than they want, then sure, that's an actual problem that needs to be addressed.
But if the reason is that people just don't feel like having 2 or more children, well, that should be up to them, no?
But if the reason is that people just don't feel like having 2 or more children, well, that should be up to them, no?