As a former ab initio instructor, taking the average 18 year old American and a young ab initio student at a foreign airline is apples and oranges.
By the time we got a student at our flight school that began training, he had already went thru six to eight months of extensive testing, met education requirements, strict physicals and was probably one of ten people that were interviewing/testing for that training slot.
Meanwhile, anyone with credit enough for a key loan or enough parental backing in this country can show up and start flight training.