If you open a lot of web sites every day you will be familiar with the challenge caused by having 20-30 tabs open in a browser and navigating between the tabs, especially because there is no differentiation between a tab that runs a web app and a tab that is simply a web site you opened while performing research or just casual browsing. You could of course close a tab once you are done with it but who has the time to do that?
There is a solution to this problem: You can add your browser tab to your Desktop. HowtoGeek posted a good article on how this can be achieved: https://www.howtogeek.com/141431/how-to-turn-web-apps-into-first-class-desktop-citizens/
TIP: You can also add the web app to your Task Bar by right clicking on the Desktop and selecting “Pin to Taskbar” (Windows 10, but a similar function is available for all other operating systems).