You can build as many cryptocurrencies as you want to. They aren't bitcoin as they don't have the history of bitcoin which means that they aren't the same.
Only bitcoin is bitcoin, because only bitcoins has the history they have.
Each coin has a unique history. You can create as many forks of bitcoin as you want it doesn't change the fact that there is only one bitcoin.
Does that mean that paper money isn't scarce?
Dollar bills, of course, are protected from counterfeiting, in the same way that bitcoins are.
So no... not the same.
First of all, I COULD sell my stale2002 dollars for real dollars, at market price, as long as I am not lying about what I am selling.
The price of my sale2002 dollars would probably be ~0, but I am still not breaking the law.
If you fork Bitcoin, you can't redeemed your forked coins for real Bitcoin, either.
It would be a completely new and different currency.
The same exact thing is the case with my new paper bills.