It would be useful if Helix could warn the user at startup when there is no runtime directory found. My first thought is the statusline, though if you open helix with a particular file, it might be taken up by LSP status message.

People often pop into Matrix to ask why their syntax highlighting isn't working. They sometimes run hx --health for a particular language and see tree-sitter parser: None but don't know that that is a problem with the runtime dir.