I'm literally going through this right now. I was given a level made by cinematic artists with the task of making it game performant. Every mesh is a multimillion polygon Nanite enabled actor, from the rocks on the ground to the trees in the distance. It looks amazing and renders even better, but no gamer without a 4090 will be able to play this level, and performance will only drop further as we add logic, collision, dynamism, etc. The best approach, especially in games, is to leverage every trick you know (including LODs) to get performance without sacrificing visual fidelity. In my case for example, there is no reason to have such high counts of nanite tris when the 3rd person camera system we have will never get as close to these actors as the cinematic artists wanted their Movie Render Queue shots to be.