Pressing F5 in a browser to see web page changes is not a big deal. But it is a context switch nevertheless, breaking your flow. And it becomes progressively irritating when you edit multiple pages or want to see them in multiple browsers.
Browser Link is a Visual Studio feature to refresh your web application in several browsers at once just pressing Ctrl+Alt+Enter without leaving the editor:
The recently developed HTML 11 extension offers a different approach to show static and dynamic web pages you are currently editing. The preview is displayed in a Visual Studio tool window using embedded Chromium framework: