You don't need to finish to learn.
>The skills are not transferable
I've never seen a statement so wrong. I taught myself how to program with Unity and I showed off my game during an interview and got my first salaried job. Definitely wasn't a game industry position, the point is they made mobile apps and I had a game on the app store.
Unity uses C# and it's not radically different outside of Unity. It's much more effective to learn by building projects , vs going though a learn to code book.
I want to make amazing games, programming is merely a tool for this. For my current project I actually have a web component ( Flutter Web is the most fun I've had in years) that integrates with the game.
I don't get what the author is trying to say. You used Godot which is known to be much rougher around then edges than Unity. You're then upset it takes longer to get things done.