A GTX970 it’s not mid range hardware, it’s a 7 years old GPU, an old ass card for this game. Mendoza level is the most demanding, and it runs decently (I wouldn’t say perfectly) on a true mid-range hardware like as shown in this video.
I’m not saying that there aren’t places to be optimized or with issues, but we are far from the performance we got with HITMAN 1 even on high range specs, or HITMAN 2 during the release without DX12 where the optimization and stability was bad on almost all levels until march 2019.