p.s. imo stupid to just to compare tech part, when coint is trying to give some business value
Why is it stupid? Particl is a privacy platform which has a native privacy coin, PART. It only makes sense to compare it to other privacy coins as well to see what features it has and what features it doesn't have. I agree part of a research into crypto projects is about determining what "business value" the project has, but another important aspect is to study the technology as well.
As for the core of your question, who will use the marketplace if eBay introduces crypto payment...here's my personal opinion.
Particl is an open-source and decentralized privacy platform designed to work with almost any coin. The end goal of the platform is to create a brand new decentralized economy independent from exchanges and the fiat system. In a way, this is taking Satoshi's initial vision and pushing it a bit further. Whereas Bitcoin is a decentralized currency that, in most cases, still requires services from centralized parties such as exchanges, Particl aims to bring the entire ecosystem within a decentralized, natively private framework.
Again, Particl is a platform, not just a marketplace or a coin. The Particl marketplace will only be the first Dapp of many more to come, all with the end goal of furthering our vision of a completely decentralized and alternative economy independent from the fiat system.
So to understand why people would use our decentralized marketplace, you have to understand the bigger picture of Particl being a decentralized platform. We want users from all crypto communities to be able to do whatever they need in a decentralized and private fashion. We want everyone to be "freed" from centralized services and be part of an alternative economy.
I think the recent rumors from South Korea and China regarding banning centralized trading exchanges and how much of an effect these centralized parties have over crypto couldn't be a better example of why we need these services to be decentralized. Does it make sense to you to be trading your decentralized currencies on centralized exchanges? For me personally, it does not, the same way it doesn't make sense for me to have to cash out of crypto or use third-parties to purchase stuff online.
I'm sorry for this long ramble, but I'm trying to put into words the importance of creating an ENTIRE decentralized ecosystem rather than just a decentralized currency. Decentralized currencies are just not enough to truly break free from the centralized banking cartel economy, you need the whole ecosystem to be decentralized. The privacy marketplace we are building is the first step in that direction.