sosein

While counting apples might be a useful example for teaching children, they're hardly the only thing there is to count. The putative abstraction isn't even in the number "one", the abstraction you're complaining about is in the chosen category of "apple". In other words, the fact that something can be comprised of many things does not change how many of that thing there are, nor does it reveal some deep unnaturalness of numbers. It at best casts doubt on our delimitation of objects.