A prominent open-source dev publishes their findings as to what's going on with Starfield's performance, and it's pretty darn strange.
According to Hans-Kristian Arntzen, a prominent open-source developer working on Vkd3d, a DirectX 12 to Vulkan translation layer, Starfield is not interacting properly with graphics card drivers.
Yes, have you even played bg3? It stutters way way more and is plenty enjoyable. They both did a mid tier job of optimization.