Is there an easy way how to determine that it did really come from the original creator?
Nowadays, imitations of something is common. So how do we know that he is the original creator of that item?
And that he is giving the platform the privilege to sell his artworks? It is quite difficult that once you purchased, you found another similar item from a different creator.
That will give less value to what you just purchased. And you are just screwed of this NFT hype.
How do we verify blockchain transactions? With the tried and true signing from the address.
If the owner/creator can verify (sign) from the wallet that created the NFT, then it proves he is the owner. That would require the NFT creators to also give them (the owners) the private keys to the generating wallet.
And giving the platform the privilege is easy. He connects with his wallet, and approves a smart contract that automatically ties the NFT to the platform, and automatically disburses any sum sold minus commissions.
Anyone can imitate, true, but you always have your unique item. Anyone can fake the Mona Lisa but there is just the one sitting in the Louvre:)