I assume by 'native' you mean 'white'? Looking at the students/faculty of elite schools/research labs and staff of top companies, I see plenty of highly intelligent and educated non-white immigrants producing great work (sometimes they even make up the majority of these elite groups).

And many (most?) Western countries do provide various incentives to have kids, as well as Asian countries, but the incentives don't ever seem to work to get above that 2.1 replacement level, so Western governments are 'worried'/concerned about birth rates, but boosting them significantly not an easy thing to do. Especially when part of the reason might be that people simply don't want more than 1 or 2 kids these days regardless of finances.