I work for several NFT art projects.
None of them are scams. I know many people who work on other NFT projects which aren't scam as well.
They are all on public blockchains, perfectly functional with relatively healthy communities.
I think you are cherry picking the scam projects by using the word "primarily". We hate scam projects just as much as you do, they damage the reputation and trust of whole ecosystem.
NFTs are already centralized and primarily used as scams. If your non-scam NFT is blocked by OpenSea, it might as well not exist for the purposes of selling and re-selling.
Where NFTs are not used for scams, they're being implemented in a proprietary blockchain and used as a method of extracting more money from customers with no new benefits (it's not like customers can re-sell their NFTs; see: proprietary blockchain).
The only thing I potentially see as valuable from web3 is cryptographic customer identification - but this is something we've had for years (client certs), but which never took off. I don't see how "web3" will change that.