I just want to add that I have also been having lower FPS compared to UE4. I created a new ThirdPerson project in UE4, made a new UE5 project and migrated the ThirdPerson stuff from 4 to 5. Then I turned off Lumen, Nanite and any other new performance settings and I am still getting 30% less frames in UE5 than in UE4.
I guess I could be missing a load of new settings that ruin the performance but who knows what they are? It would be nice if Epic could create a template or show us all the settings to be able to get back to UE4 performance when you aren’t using Lumen or Nanite if that is even possible!?