That's not how it generally works.If someone leaves the Faith and devotion unto The creator because of believing some man made beliefs whether proven or not....His/ Her heart was not really in being Christ like.
What typically happens is a kid is told from an early age that evolution and "billions of years" are fake, made-up hoaxes by God-hating scientists. As they get older they're given specific arguments like "there are no transitional fossils", "no new species have evolved", "no new genetic information has ever evolved", and such. But when they get to high school, they start to find out that some of those things are just wrong. And those that go on to college and take even basic college courses find out definitively that just about all those young-earth creationist arguments are factually wrong.
The problem comes in when they've been told all along that you can't be an "evolutionist" or "believe in millions of years" and be a Born Again Christian. It's one or the other...can't be both.
So these kids know what they've seen with their own eyes, and they know which side of the issue has been lying to them, so a good number of them figure, "If this is what I have to believe to be a Christian, then I can't be a Christian".
The schools are getting better and better at teaching science every year, so the more fundamentalist Christians push this false dichotomy, the more kids they drive from the faith.