After upgrading to Windows 11, you have Chat in the taskbar. This is really a Teams personal client, meaning that you end up with two Teams clients on the PC. To make life even more confusing, if you search Windows 11 for Teams, you see the personal version suggested first. Some pruning of clients is needed.
Modern browsers make it easy to pin websites to the Windows desktop and taskbar. Using OWA in this manner is great when network connections aren’t too reliable, like the flaky connections you often have on airline Wi-Fi networks. Other Office 365 apps work fine too when pinned from the browser, like the Admin Center, Planner, To Do, and Stream.