Scarcity is necessary but not sufficient. What sets BTC apart from NTFs is its fungibility. In theory, there are an infinite number of potential cryptocurrencies, sure. But everyone has already embraced bitcoin (and a small handful of others), and replacing that userbase is an incredibly tall hurdle.
On the other hand, minting a new beanie-baby-NFT takes less effort than making an actual beanie baby.
On the other hand, minting a new beanie-baby-NFT takes less effort than making an actual beanie baby.