But technically, as far as I know, they are both pretty similar.

So where is the difference? Are these just small details which VSCode got better? Or are there bigger things?

Or why else did VSCode actually won?

I have used both in the past. VSCode seemed a bit snappier, which is an important aspect for an editor. But I'm not sure if this was really the case actually. Or also, why there would be such a difference. Both used Electron, and I assumed both would use similar techniques for the editor.