Counterparty is basically an early version of Ethereum which was built on top of the Bitcoin blockchain as a protocol whose transactions get settled with BTC while paying fees to the Bitcoin miners. It was most likely abandoned because it scales really poorly. But in the summer of 2021, when the NFT mania was at its peak and Ethereum was dealing with ridiculously high fees, bitcoiners remembered about Counterparty and seized the low demand for Bitcoin block space to bring some old art back to life.
While some will discourage the use of Counterparty and recommend Raretoshi on Liquid or RGB Spectrum on the Lightning Network, the reality is that none of these are as secure or as decentralized as the Bitcoin blockchain. Also, none of them is guaranteed to live for as long as the base layer itself. And since there are lots of collections which exist on Bitcoin, there will be collectors to acquire an interest in them. The goal is clearly not to “scale”, but to grant the highest security and longevity to assets.
Counterparty has been pronounced “dead” many times before, but it made a couple of comebacks specifically because it’s built on Bitcoin and requires minimal maintenance – the assets will always exist and they’re secured by a global network of miners and full nodes, so it’s only the user interfaces (wallets) that need improvement from time to time. Your NFTs may cost more to create and transfer (as compared to centralized platforms like Liquid and Ethereum), but they are also safer because shutting the network is virtually impossible.