Using the blockchain as cloud storage is not really scalable. NFT protocols don't actually store images directly and instead what you are paying for is proof that you own something that is outside of the blockchain. There's been some instances where people's NFTs disappeared from their wallet because Metamask couldn't connect to a third party API. As long as you are relying on centralized databases then their is no guarantee that your NFT will last forever.
It is true that NFTs may disappear from the wallet due to connection issues with third-party APIs at any time, reflecting potential vulnerabilities in the current infrastructure. If a centralized database or service goes offline or encounters technical difficulties, the associated NFT may be lost or inaccessible. but, I assume there will be a Solution that will emerge to overcome this challenge.