What are the main disadvantages of Unity3D?

The main disadvantages of Unity3D include performance limitations for advanced graphics and large games, as Unity may not be as fast as engines like Unreal for AAA projects. Unity’s flexible system can result in larger app files, affecting mobile performance. Professional licences can be expensive. The many features in Unity3D create a learning curve that may challenge beginners. Some advanced graphical features also require additional coding or the purchase of third-party assets, which can make projects more complex and extend build times.