RE Engine: Monster Hunter, REMakes, DMC. All run beautifully
Idtech: Doom 2016 and Doom Eternal are super optimised on low end hardware
Then you have Unreal Engine 5 which needs top end hardware to run (Remnant 2, Lords of Fallen) and
Gamebryo/Creation which still has bugs from Morrowind in Starfield.
Not sure if related but City Skylines 2 needs several times $$ investment for slight improvements over Cities 1 on Unity
Now a splash screen either makes me smile or cringe. Just wished everything ran RE engine
the games/engines you cite as being “extremely well optimized” are both a lot older than UE5 and do a lot less than some of the “less optimized” games discussed (i.e. simpler lighting, no geometry virtualization, simplistic simulation, very static environments, etc.)
these are very apples and oranges comparisons