This is an on going issue that really leaves MS 365 behind the competition. I have been reading threads that go back a number of years asking why the desk top version of MS Teams does not support multiple accounts unlike the mobile app that does. Why is anomaly? In past threads it is suggested that this will be rectified. Please Microsoft when will this be the case as the earliest thread that I have read goes back some three years. Do
Also, I do still find it relatively easy to achieve the same thing using multiple profiles with a browser such as Edge Chromium but of course the web limitations apply, but to be fair the web version does most things.