How to remove the Live Share button?
Solution 1:
Uninstall the Live Share feature via Visual Studio Installer under individual components
Now the button is gone.
Solution 2:
You just need to go to Extensions -> Manage Extensions, look for Live Share, and disable it.
Solution 3:
You can hide the Live Share and Feedback buttons area with Visual Commander: https://visualstudioextensions.vlasovstudio.com/2019/03/19/freeing-screen-space-in-visual-studio-2019/