Developers can issue their own tokens on ethereum / PlasmaChain, there's no need to build their own sidechain to do that.Benefits of building their own chain are they can choose the consensus model, how many validators there are and how they're chosen, and if / how those validators are rewarded. Basically they have full control over the chain and it's fully centralized until they choose to open it up, so they can set all the rules. This may make sense for very very large applications that need their own dedicated DAppChain.
Advantages to using the shared chain are you just focus on building your app and don't worry about infrastructure, it's built up of a decentralized set of validators so you don't have to secure your own chain against attacks, you get to take advantage of the existing user base and services on the chain like the marketplace, users are more likely to trust your dapp (they don't need to verify and trust your new chain), etc. We have @loomnetworkdev and @loomsdk chats which are more technical if you need some help figuring out the architecture.
By LukeHall. August 13, 2019