Thelasko quotes gHacks:
Linux Mint 20.1 comes with a unified file system that sees certain directories being merged with their counterparts in /usr, e.g. /bin merged with /usr/bin, /lib merged with /usr/lib for compatibility purposes…
The developers have added an option to turn websites into desktop applications in the new version [using the new Web App manager]… Web apps behave like desktop programs for the most part; they start in their own window and use a custom icon, and you find them in the Alt-Tab interface when you use it. Web apps can be pinned and they are found in the application menu after they have been created.