Battery life on a smartphone just doesn't cut it for longer rides. Also, your opinion whether this is the right device for you really shouldn't inform a cold vote, the idea is if this is a good deal or not. Can you find it elsewhere cheaper, has it been a lot cheaper recently, is the retailer a shyster? COLD. If you don't think people need this? No need to vote.
Honestly, I went through that thought process too, maybe 5 years ago - then I tried one and suddenly it made complete sense and I would never go back to using a phone. Phones are just not designed for this purpose. It's very difficult to use a phone on the move or use a touch screen with gloves, smartphones are fragile and expensive, rain, screen glare, battery life, GPS accuracy, etc can all be issues. I'm now a club cyclist and I can say with confidence you're unlikely to see any riders with a smartphone attached to their bike on a club ride, let alone faster chaingangs, TTs or races. There are many articles on the advantages and disadvantages, like: Cycling weekly
These devices are redundant nowadays. Most people have a smartphone which can do just as good a job. Theres many Apps available. I have used Endomondo for years. Its been great for cycling and tracking walks with the dogs. Cold for me.
No brainer. Heat.
I somehow lost my wahoo (I'm certain it's here somewhere I just can't find it) so I might have to buy another at this price. So much better than the Garmins I've had. I've used it to help navigate for both cycling and also trail running since the map is really clear and it's small/light enough to go in a pocket and still lasts all day. The non-touchscreen interface is very easy to use, especially when hammering down a mountain. It also has lots of integrations with various online services. I don't think there are any bad points. I wish I could find my old one!