Is the final look of a model,in-game work done in a modeling software or inside unity?

Hello ,so this question is mostly directed to people, that have experience with the modeling and composing part of a game .As am fairly new, with all this game making experience, especially the modeling part,there is a heavy blur concerning some things about it. I managed in my free time to make a very simple 3d game, with 2 scenes the first 1 is a level the second one a boss, but before i go on and try to do more stuff and testing and implementing features i want to learn more about modeling and how to create decent looking visuals, in unity or my modeling software(blender).I have a model that i made it's just that it doesnt look "good" it's shitty actualy,it's the model uv mapped with a textured slapped to it.

So having said all that as background info ,i spent these days looking on custom shaders,lightmapping in unity ,in parallel with blender tuts for scene composing and assigning textures how to make them look realistic.The thing is...for example let's say i want that cartooney/shiny style visuals of the new Ratchet and clank.What is it that gives you this feel?
Is it making a good texture/normal map/bump map/whatever map?
Is it baking the texture properly into the object?
is it the use of custom shaders?
is it the use of light in the engine?
I am lost kinda in the workflow here as you can tell probably modeling>uvmapping>texturing>import to engine>polish-define?! Also i see sometimes people talking about using gpu settings or software of their gpu to affect the image? i realy don't know...Any, literaly any type of guideline or tip is welcomed and ty for it.