Such keyboards are good for people with wrist, shoulder, blood flow, etc. problems. But for the majority of computer users a regular keyboard is good enough - just take a short rest now and then.
In my opinion rectangular keyboards aren't good enough at all. They're uncomfortable and bad for your wrists, and the only reason people are using them are because: they don't know any better, computers (laptops), by default, come with rectangular keyboards, force of habit, the cost involved with buying another keyboard or having durable wrists/being young and not suffering from deteriorating body.
I started using Microsoft Natural Keyboards mid 90s, and moved onto Arisu layout mechanical keyboards a few years back when I first learned they were an option. They are so much more comfortable than rectangular keyboards. It's not even close, even without all the customization options available for switches, keycaps, tenting, etc.
I'm really glad I took the plunge and switched to a keyboard that I could program to move the action away from my pinkies (I moved the character blocks outward and got real creative with the two new columns between g and h).
Had I waited longer I think it would've gradually dampened my enthusiasm for code, just by association.