An open source text editor that isn’t as “bloated” as VSCode? Sounds like … all of them, really, try Emacs or vim or nano or vi and maybe you’ll find something you like. But if what you want is “VSCode with all the features I use and none of the ones I don’t,” you’ll probably have to make it yourself (or at least be more specific).

Have you looked into lite (https://github.com/rxi/lite)? It's quite minimal, but easily extensible and is very lightweight.