You are comparing apples with pears. Sublime can't be compared to VS Code because the former is basically an advanced editor while the latter is an IDE (like PhpStorm or Atom).
And I highly doubt that many users switching from Sublime to VS Code. They use one or the other for a specific reason, like a blazing fast and distraction free editing experience in Sublime - something you do not have in VS Code or any other IDE, imo.
I use VSCode for programming (Typescript), but it's also become a great replacement for my usual native text editor (Notepad2). I love how performant yet, feature-packed and extensible it is, and since I keep my notes in Markdown format, the `yzhang.markdown-all-in-one` extension is really useful.