It’s only “natural” up to a point. I’ve never seen 10^100 of something so there’s that.
What about 6 cards? 7 cards? At what point does it become "not natural"?
This doesn't mean it's not a "relevant thing to talk about". It just means that these mathematical constructs while useful don't maintain a direct connection to reality, kind of like complex numbers.
I really don't understand what this means in practice. If there are exactly 50 rocks in front of me right now, I can't talk about 51? It doesn't maintain a direct connection to reality to talk about what would happen if I threw another rock on the pile? Or if that's connected cause another rock exists, what about if I have exactly 20 chickens, and I want to talk about what would happen when another is born? Is this "connected to reality" and "a number of natural objects"? Or "the cardinality of a set" instead?