> JSX would be a non-starter without IDEs helping autocomplete, linting/format, syntax coloring, and webpack/babel to do the compilation.

and then you immediately go on to say this:

> tagged templates could reach at least the same level of DX as JSX if the community invested the resources to make that better.

So, tagged templates are also non-starters without IDEs helping autocomplete, linting/format, syntax coloring.

> i'm not saying it's the right solution for a standard, but it would be way better than jsx, since tagged templates are already a standard.

They are strings. There's no magic in tagged templates that somehow make them immediately better for some custom non-standard syntax compared to JSX.

You can't just plop a string containing lit's custom non-standard syntax into an IDE (or a browser) and expect it to just work because "it's tagged templates are standard".

For the purpose of templating in the browser there's literally no difference between standardizing a custom syntax based with JSX or tagged templates.