WhatsApp is available on macOS… sort of.
You see, since until just recently, macOS users didn’t have access to a standalone WhatsApp app. When they eventually did, whatever they got is just a wrapped version of WhatsApp Web, the desktop browser-accessible version that has been around for a while.
Now, macOS is on the verge of getting a true “native” macOS app. That app is up for testing and if you are interested in helping to test drive it, you can just go ahead and download it.
The native app is expected to fully replace the wrapped one available on the App Store in the coming days.