Well, we’re here on a web site discussing it, and the top two recommendations are “build one yourself from parts” and “buy a used one in cash”.
Seems to me that it’s the very definition of unrealistic if the real world has almost no examples that do it.
As an internal implementation detail, it’s fine and pretty standard. Exposing it to the end user so that they have to know whatever janky-ass domain and capitalization you picked to run your application is braindead.