Okay tested it on RTX 3060 Ti.
View attachment 4315511
View attachment 4315512
Windowed mode, lowest possible res.
barely 25fps. 99% GPU usage, 80*C+
Usually on RTX the biggest offenders are Lumen, Nanite, RayTracing, PathTracing, DLAA, Global Illumination, Shadows, Reflections.
if you don't have Lumen, Nanite, RT, PT, DLAA enabled, then it's likely Global, Shadows, Reflections.
If you can't find a way to fix any of this, don't stress too much it's not entirely your fault, you picked a heavy engine.
Unreal Engine is especially heavy on GPUs, it's infamous among the reddit "FuckTAA" community for it's poor engine optimizations that are hidden behind TAA and DLSS.
Even Nvidia went out of their way to Mod the UE5 code for their own personal use, and you know things are BAD when a Graphics Card manufacturer has to fix your homework (engine code).