How hard is it for those projects to add the functionalities Stratis have? For example, let's say a project pretty similar to Stratis does not have fully independent sidechains yet. What hinders them from getting it? Is it hard to do technically? And if it is fairly easy for other projects to develop/copy same technologies as Stratis, why will stratis be a better pick?
It can be, however that's why we're working with the industry directly to build a set of rules that everyone can follow so there can be as many identity providers as their are places like TuneCore. It changes the places where businesses can operate. By the same token (pun intended) you could simply follow all the rules yourself and still enjoy all the same protections and no cost.