Siri Shortcuts is actually 3 different things, all with the same name. Two of them are for the every day user and are brain dead simple: Siri's machine learning will monitor your activity and suggest shortcuts on the widgets screen and apps themselves will allow you to turn certain actions into a Siri shortcut with a single tap. Then there's this Shortcuts app which is clearly aimed at power users. Everybody gets something here.
It may not seem like it yet because app developers have yet to release updates to their apps, but Apple has gone from the back of the pack to beating Alexa to first place. Alexa needs to release specific "skills" while Siri now has the world's biggest App Store as infinite "skills". Anything you can do with an app, Siri could potentially do with each app's developer easily flipping a switch while Siri itself can enable these actions that it sees you regularly performing. It'll become more apparent as apps get updated and as you use iOS 12.
Finally, Siri Shortcuts is the front end of a much more far reaching change. The architecture of how Siri works has been rebuilt for Shortcuts and that architecture will serve as the foundation for Siri itself, replacing the old architecture which was limited because it wasn't scalable with this new architecture which is infinitely scalable.
If you've been asking for Siri to be fixed, this is it. It's here.