In the realm of photorealism, optimization is one of the most important aspects every developer will have to deal with. And while it may seem attractive to just slap 4K Quality Textures onto your models, that’ll make your project that much more demanding.
https://dev.epicgames.com/community/learning/tutorials/OPy3/unreal-engine-5-how-to-increase-normal-map-texture-quality-making-2k-textures-look-great