"The easy-installer beta version supports 15 devices"
This is the #1 problem, but it's not /e/ developers fault, as supporting devices is a time consuming and costly activity, and the risk of bricking an expensive device is just too high for normal users to want to try. Manufacturers are to blame. It's not a technical problem but rather a political one; manufacturers should be forced by law to unlock boot loaders and publish at least the bare minimum documentation enough for porting software to devices that became obsolete either by the introduction of a newer version, or after support has ceased. Until that happens, I'm afraid we'll see more and more projects supporting only a very small part of the available devices.