I have a client that had 4 Amcrest POE (Dahua) bullet cams on an Amcrest POE NVR for about a year before he called me. During that time he said he tried his best to get it set up and it was working but he said it missed motion events, found it cumbersome and clunky, hard to locate events, make snapshots, export video, etc. so he called me, discouraged.
I gave him a HP dc7800 SFF that I had increased RAM to 8GB, put Win 10 and
Blue Iris v5 on a Samsung 240GB SSD and a 2TB WD Purple HDD for the video clips. Set it up to stream the 4 cams to BI via channels of the NVR, dialed in the motion detection, alerts, etc. , showed him how to work it, review events, etc....that was 3 years ago. I called him after a few months because I had not heard from him and was curious; he said it all worked great and he found it easy to review clips, etc.
Now he's a VERY non-tech 56 year old that paints semi-truck trailers and installs boat docks. His Android cell phone is his only tech item and even that challenges him BUT he admits it and he is OK with that as he very well should be..... not all of us are techies....and not all of us can weld, paint and create masterpieces of mechanical function and practicality.
Bottom line: Blue Iris or NVR ?.....what works for you is what you should use, IMO.