I have had the good fortune to have never worked in a codebase with the characteristics you describe. But I have seen some issues with theCar.fuel(), and that’s

I have had the good fortune to have never worked in a codebase with the characteristics you describe. But I have seen some issues with theCar.fuel(), and that’s generally around mutability and crazy side-effects. I think most of these are pragmatically overcome by adoption of functional paradigms and function composition over inheritance or instance methods.