NFTs are representing ownership of physical or digital objects.
As far as physical ownership goes, it comes from what ownership record keeping system are you going to trust? For land, we have trusted state provided system so far. This can change with NFT like technology, provided people including the state trust it to manage those records.
For digital items ownership, there is literally nothing that prevents others from getting a copy of your item. You just get to claim the ownership rights to it, which doesn't mean much when everyone can get a copy of it, like you do. It's essentially reduced to bragging rights, claiming you own it, on a record keeping system which people trust. But would people even care to trust a system for ownership when literally anyone can hold a copy of that digital item in their possession? If someone else copies it over to another record keeping system, what difference does it make? Not much. There isn't much value in bragging rights to ownership, as much as it is in possession, which in digital items isn't securely feasible in this manner.
A decentralized network doesn't care for vision, it functions as per what its participants want. What you are describing, is a problem in centralised network, which Ethereum is. So, you are technically right, but let's not confuse the interests of the creator is same as the interests of the users of the network.
Miners are not supposed to serve anyone but themselves. Everyone for themselves. A right system economically incentivize the right action by design, like in Bitcoin. Important to understand the first principles before judging any distributed system.
As far as physical ownership goes, it comes from what ownership record keeping system are you going to trust? For land, we have trusted state provided system so far. This can change with NFT like technology, provided people including the state trust it to manage those records.
For digital items ownership, there is literally nothing that prevents others from getting a copy of your item. You just get to claim the ownership rights to it, which doesn't mean much when everyone can get a copy of it, like you do. It's essentially reduced to bragging rights, claiming you own it, on a record keeping system which people trust. But would people even care to trust a system for ownership when literally anyone can hold a copy of that digital item in their possession? If someone else copies it over to another record keeping system, what difference does it make? Not much. There isn't much value in bragging rights to ownership, as much as it is in possession, which in digital items isn't securely feasible in this manner.