I hadn't considered it until I met a couple this summer who were bikepacking from Seattle to SF. They told me it was one of those items you don't think you need until you get it and then you wonder how you did without it.
It's like blind spot monitoring and rear cameras on cars. I'd been driving without those for decades, but now that I have them I wouldn't buy a car without them.
The Varia radar also connects to the Wahoo bike computer, which is great.