In Unreal Engine, grass can be distributed using Foliage Mode, Landscape Grass Types, PCG, or custom systems. Foliage Mode lets you paint instances onto surfaces and batches Static Mesh Foliage using hardware instancing; Actor Foliage, by contrast, retains a cost comparable to placing standard actors and is not suitable for thousands of blades.
https://dev.epicgames.com/community/learning/tutorials/ryMGx/stylized-grass-implementation-for-video-games-in-unreal-engine-5-7