There is a program for Windows called StarDock Groupy, it can group windows into tabs. It could be useful, but not as much because of horrible rectangular design. I cannot extract several WhatsApp chats from rectangle, to group them with office document we discuss. There are multiple desktops in Windows, but rectangular programs do not permit sorting different chats to different desktops.
If web app permits opening in several windows at once, then drag-n-drop does not work between windows as good as it works in native apps like iChat and Adium.
I often see that applications pretending to be native, are in fact based on browser, and inherited all constraints, and are forcibly rectangular. Such quasiapplications, of course, no much benefit to install natively on desktop.