I would argue that having the designer put the "heart and soul" into a game is possible, but not ideal. When an artist or developer is also a/the designer they

I would argue that having the designer put the "heart and soul" into a game is possible, but not ideal. When an artist or developer is also a/the designer they can make changes and decisions more smoothly to create certain effects. There is no way a game like the first Portal could have been designed by a game designer, it started as a research project by a developer. Then there are games that do very innovative with the art blending it seamlessly into the design in unconventional ways, like Antechamber. I think there are plenty examples of games that buck the mold too hard for a conventional designer to have been able to make them. My favorite example is Minecraft and its procedurally generated infinite world, much of the art is in algorithms that create the biomes. Cresting the top of a mountain to see the scenery on the other side for the first time is so simple to do and easy to enjoy in this game. The programmer had to be the designer and the artist to pull this off. I know Notch worked with others but this one facet had to be singular or iterative, not communicated from someone seperate after "designing". This was communicated in code and programmers and artist saw what existed and tried to build something and sharing. There is no good way for a conventional designer to convey the details of an algorithm to build forests and cave systems. It is not a fundamentally unsolvable problem, it is just presently unsolved in my experience.