It’s not the same use case. Asciidoc is closer to markdown/org/reST, i.e., simple markup languages, whereas Typst also emphasizes on presentation (layouting, element positioning, creation of complex figures, etc.). You can reproduce features from Asciidoc in Typst using scripting.
As for editors, aside from the official webapp, and the community LSP (tinymist), there aren’t that many available.
