Excellent for rapid development and testing early game concepts. Cons:

When you build a Unity project, the engine identifies every folder named . It then packages all contents—including textures, prefabs, audio clips, and materials—into a single serialized file called resources.assets . This file also contains an index (a lookup tree) that allows the game to find these assets by their file path at runtime using the Resources.Load() command. 2. The Pros and Cons of Using Resources

Everything in the Resources folder is included in your build, regardless of whether it’s actually used in a scene.

Resources vs StreamingAssets for mobile. - Unity Discussions