These are at least 3 different questions:
1) Why should I use VS Code in general?
2) Why should I use VS Code online? (the articles topic)
3) Why should I use VS?
The answers might turn out completely different.
Personally, I have for my main languages (C++ & Python) full IDE's (VS & Wing IDE). For quick Python scripts, VSCode is considered an option that I use rather often.
In what VSCode shines is - as also other commenters mentioned - his plugin eco-sytem. This has true swiss-knife traits. So I'm using it for many secondary and ad-hoc technologies:
- CMake files
- Julia
- GPS files
- JS files
- LaTeX
- JSON
- XML
- CSS
- Markdown (vanilla, asciidoc, ReST)
- remote editing