Yes and no. Many aren't less 'gifted' just less able - they don't have the right language background for school, dont have the easy ability to study at home, et

Yes and no. Many aren't less 'gifted' just less able - they don't have the right language background for school, dont have the easy ability to study at home, etc. 'Grammar schools' (or something similar of a different name) are reasonably common in UK and its colonies and attempt what you are asking for - with very well documented positives and negatives. There is definitely a massive issue of equality where children feel they aren't in the 'good' school this becomes an excuse for not bothering with school and then life. Equal education brings a lot of benefits to society at large.