> Regardless, though, it's open source

Some major bits and pieces of the base editor are, but little of what makes vscode into a usable productive tool (namely, the refined extensions and LSP implementations around it, i.e. what users come to expect when they install it in the first place) is open-source. vscode put a lot of marketing effort into being perceived as open-source so to buy sympathy from eventual users.

Let's stop at "vscode is open-source in a very narrow and limited capacity, and thoroughly deceptive in its messaging".

I would honestly love to see the result of a survey asking vscode users whether they think they are using an open-source product, and how much of that is actually verified based on the extensions being used.