Less than 300 lines into way over a thousand? I don’t agree but duly noted. Please, this article is not about MVC but the use of a particular class called Field Class. The Field Class has been a good alternative in my experience. The MVC implementation is a design pattern, and an array of free articles on that separate subject can be found in MVC in Flutter.
As for the approach taken here, yes, it does do a bit of ‘hiding away’, but of course that’s the point. It does a lot of the work for you — you merely enter the parameters you want.