I assume that this leans to what you use vscode for.

In my case, it replaced Jedit, Emacs, Notepad++ as the tool for working with text and some source code. "Real" Development is handled by Visual Studio.

So it's used as a scratch pad, documentation snippets, formatting various XML/JSON snippets...

In my context, my favorites are: 'Markdown Preview Mermaid', it's much faster for quickies than Visio. I also use the "Edit csv" (for all the inevitable CSV files, yeah yeah, Excell...) and "SQL server" to replace SSMS (faster load time...)