The main differences that I can see between an NVR and a PC dedicated to running
Blue iris are:
The NVR will have a built-in POE switch, so you won't need that.
But:
The NVR won't likely use any less power than a modern PC, since in effect the NVR is a PC in a box, with an already-loaded operating system and special purpose program that it boots when you fire it up.
The NVR won't be as expandable as a Blue Iris system.
The NVR won't likely be upgraded every few weeks the way Blue Iris is. You can ignore the updates or let the computer upgrade whenever you want, giving you new features and capabilities.
The NVR won't have the easy access and features for reviewing, moving through, and playing clips.
The NVR may not have any easy way to find, define, and export segments of videos.
The NVR might not have as good of ways to export stills from videos.
Both of those are really nice and easy, especially considering that you're then using a PC with all of the connectivity, software, and possibilities that a PC brings to sharing videos and stills.
The NVR may be more limited in how you can access your video from your phone, remote PCs, tablets, etc. This is all really nice when operating through a VPN to your mobile devices and offsite PCs.
It does take some extra learning and work to get things set up this way, but once you do, you'll not only have a great system, but you'll have learned a lot about cybersecurity and probably end up with better security for your whole local area network and all of the devices on that network. This is becoming more of a concern all of the time, so it's nice to be "plugged in" to a community of folks on this forum where you can learn about it all and get updated on emerging threads quickly.
As
@aristobrat said above. You're on a forum of folks who have been through all of this before. So we're just trying to help you jump over some of the mistakes most of us have made as we've gone through the evolution from initially just wanting a cheap, fast, easy way to remotely view and locally record some cameras to wanting systems that work better for us and are safer.
There are a lot of extremely enticing camera systems available right now. And they're very seductive because they're so easy to set up and cheap to buy. And frankly, a lot of them work pretty darned well!
But in the end, most of them are very dangerous for your network, and probably won't do as good of a job as what you might choose once you know better what questions to ask. It's like most hobbies or endeavors. When we start out, we don't know enough to know what to ask, and most of us end up learning the hard way and have a closet full of gadgets that we bought as we worked our way through the learning process and outgrew them.