When you use an SSD for applications with high write intensity like DVR/NVR, it won't last long once you fill it up. NAND devices have limited write cycles, which gets worse with higher density devices like TLC or QLC, despite the aid of wear leveling techniques. There's a reason consumer drives like the T7 don't advertise specs. for lifetime writes, just recommended uses (which doesn't include continuous video recording).
I'm not sure I agree with this. I shoot and edit commercials for a living and I've used a Samsung T5 1TB SSD for recording 4k video from my cinema camera for a couple of years now and have had zero degradation. I don't know if that applies to this kind of use but those videos are far larger than what the DVR is recording.