The client was specifically designed for browsing web pages. It has all kinds of features for it. A chat client would be quite different. The file menu would load and save chats. The context menu would have chatty things in it. You have to close the application to lose any application state. We've kinda forgot how nice it is to have a desktop application. 30-35 years ago function keys where cool. I cant remember the last time I've used one. I also cant remember the last time I've used the top menu with alt keys. The browser also has to limit functionality for safety reasons.