Games are definitely not very well optimised. For one, most indie publishers are artists rather than software developers, which means that they do not have the technical expertise to properly program their applications, especially on the OpenGL/Vulkan/Direct3D side of things. Large video game corporations, in contrast, are indeed quite capable of reducing the hardware requirements and increasing the performance of their games, but they are often not willing, as became particularly evident recently with Jedi: Survivor, where a major public outcry was required for them to fix the game's performance problems, which they have done quite competently.