I'm surprised Netflix doesn't just use Cobalt like Youtube probably does, but it looks like they use their own internal thing called Gibbon. Source: over 2 years ago

The YouTube app on Apple TV is absolutely atrocious. I can’t believe either Apple or Google think it’s acceptable — it must be one of the most-used apps on tvOS, and is easily the worst I’ve ever come across. It seems to be built with Cobalt [1], so it’s basically HTML5, pretending to be a native app. A short list of flaws which have infuriated me for months: • Scrolling is completely broken. Scroll down a... - Source: Hacker News / over 2 years ago

Cobalt is this: https://cobalt.foo/. I believe that it practically replaces a browser and has small footprint, so you can use it to run web apps on devices that can't run Chrome and thus can't have PWAs via browser. Source: almost 3 years ago

I just install Linux Mint's WebApp Manager. Its a simple python program that does what you're looking for and its in the AUR. https://aur.archlinux.org/packages/webapp-manager. Source: about 2 years ago

If you only use firefox you can install this (yay -S webapp-manager) web app manager that can create a web app for any site with firefox. Since whatsapp is a simple app you should be good. Source: about 2 years ago

Here's another alternative: use the webapp client for discord. I use webapp-manager for many web apps. You could create multiple webapps running different discord accounts. Source: over 2 years ago