My impression is that VSCode is partly about promoting TypeScript, and for what it's worth it has more or less worked on me. Create a "x.ts" and type some stuff; you will see error messages immediately that are roughly as good a first experience with an IDE as I've ever had. I mostly work in Python and Swift, mostly in VSCode, and I wish the support for those languages was nearly so good.

I am an intermediate JS programmer, fiddled with TypeScript a couple of years ago and was unconvinced. Since then TS has matured a lot, and I have been exposed to it in passing from looking at VSCode extensions. If I were to begin a web project today, I would give TypeScript a try. If it weren't for VSCode my thinking would probably be quite different.

As an open source project, VSCode is a significant example of TypeScript on Electron. As a self-hosted IDE I imagine that it has been a good source of feedback for the TypeScript team. I would be very interested to know how many TS issues (checker / compiler bugs, feature requests, etc) have emanated from VSCode.