Well basically, you know how when you make a landscape about 2000 x 2000 everythings a bit triangley and low res, like not the textures, but the landscape in general, perhaps you could add a function that makes it possible to make the landscape more high poly?
You can already do this by increasing the resolution of the landscape components using the landscape tools and then in your Landscape Material you can use distance-based tessellation to get additional detail closer to the camera.
Take a look at the documentation here: Landscape Technical Guide in Unreal Engine | Unreal Engine 5.1 Documentation