The concept is cool. But we're yet to see the government becoming part of this trend. So far, the vast majority of NFTs being traded on the market are nothing more than a scam. Nowadays, anyone can make an NFT using a picture/image found on the web. This bloats underlying blockchain networks with many unecessary junk. Things are only getting started, so I have high hopes the NFT industry will improve in the long run.
But same applies to erc20 and bep20 etc tokens as well. It's because the permissionless nature of blockchain, even trolls can fill it with their junk.May I ask if the ERC-6551 is what Vitalik calls "Soulbound Tokens (SBT)"? These might become the next big thing in crypto land, as Universities/Colleges and other institutions use them for their own benefit. SBTs might prove to have better use cases than NFTs over time. Who knows when the SBT hype will begin? 
It's inspired by SBT but it's a new concept. Like SBTs but trasferrable and more.Currently erc-721 NFTs are bound to wallets, just like cryptos are in general. You can think ERC-6551 other way around, wallets bound to NFTs. "Those are called Token Bound Accounts" (TBAs).
From what i understand, for example when you normally link wallets to sites, this could make it it possible to link your nfts. As those become smart contracts themselves.
This post explains it way better than i could:
https://blog.alphapanda.one/token-bound-accounts-erc-6551-the-future-of-nft-wallets/
I am still wrapping my mind around it. It took a while for me to even get erc721 when they came, so i guess i need to see this in action before i truly get the possibilities.