I use VS Code most of the time, but the reason I always use Notepad for taking quick notes _is_ the startup time of VS Code. If they improved it, I'd be using it for both. It is an important metric for some.
Still get syntax highlighting and everything, but waiting for VS Code can be long enough to derail my train of thought.
Also, IDEA has scratch files for quick notes available through a shortcut (I guess VS Code might have a similar plugin), so startup tome isn’t an issue either.