For YOU there not might be......
You have to force a command line parameter to launch in DX12. It's not exposed in the UI, it doesn't default to it, no one will launch it in DX12 without specifically googling how to do it.
Yes, the performance is brutal in DX12, but it's clearly not intended to be run in that mode. From what I can tell it's doing ray traced reflections, but they may not even be RTX accelerated with how abysmally slow it is. Maybe something that is coming in a future patch, but currently I don't see the point in spending that much critique on a mode that the developers clearly don't intend the public to be using (your cat's body reflection is completely static for example when moving, it's clearly broken).
When/if they actually make this mode visible and indicate it's an actual option, sure.
Speaking of the PC version, the dev has acknowledged the shader compilation stutters (reminder this is not just a DX12 issue!), and a patch is planned. From
ArsTechnica's Review:
(Update, 1:55 pm ET: In an emailed statement to Ars, a representative for BlueTwelve acknowledged the PC version's current shader compilation stutter issues, then added, "the team is planning a post launch patch to fix a number of issues. They hope to be able to handle this at that time if possible." No time estimate was given.)
From my experience with the game the shader compilation stutters are actually not that heavy, most are in the first 30 minutes. At least on my system, the performance issues seem to stem more from (once again) a wonky vsync implementation, which thankfully being DX11 at least you can fix. There are moments in the game where I was dropping below 60fps with 80% GPU utilization, forcing Fast Sync clear this up - of course if you're running a VRR display you won't have to deal with this. Also some basic UE traversal stutters, and a poor optimization of some alpha effects it seems - there is a small alpha smoke effect for example that occurs from your robot companion when you overload them after firing a weapon for an extended period that can take up an additional ~40% GPU usage when it gets close to the camera which is bizarre.
Otherwise though, playing at 90% 4K scaling with slightly higher-than-PS5 settings (going from the Analista video) gets me 60+ fps in most areas of the game on my 3060. So perhaps not a stellar port (no DLSS, booo) but not sure how in the heck that SkillUp review got those abysmal performance figures on a 2080TI (50fps at 1440p!) - judging by my results, 4k maxxed should be giving you 70-80fps on that gpu.