While I understand that NFTs could be used as a receipt for a digital purchase - the NFT system would have to scale impossibly well to keep track of the infinit

While I understand that NFTs could be used as a receipt for a digital purchase - the NFT system would have to scale impossibly well to keep track of the infinite copies of infinite digital goods multiplied by the billions of people. Blockchain might be amazeballs but it doesn't seem to scale THAT well.