By the examples, do you mean the fact we are using Codesandbox embed to show code examples of the editor itself?
Lexical definitely has the foundational requirements capable of building a CodeMirror or Monaco editor, but that wasn't our initial target with this library. That doesn't mean that we don't expect the community to push it that way in the future, we fully expect that. Let's see how things go, competition is healthy! :)
Having the live editor examples on the home page be live examples of a different editor (of a different kind) is more than a little confusing. I understood Lexical to be a code editor until I came here and saw your comment. The main page even describes Lexical as a "text editor", a term used for plain text like code. I suggest embedding the playground up the top of the main page and describing Lexical with a different term.
Lexical definitely has the foundational requirements capable of building a CodeMirror or Monaco editor, but that wasn't our initial target with this library. That doesn't mean that we don't expect the community to push it that way in the future, we fully expect that. Let's see how things go, competition is healthy! :)