Huh? lit-html uses standard JavaScript. That's it. JSX is a non-standard extension. So yes it is more standard than a non-standard, and lit-html runs directly in browsers without any transpilation while JSX very much doesn't.
VS Code is as able to analyze lit-html templates as well as JSX via the lit-plugin extensions. It gives you type-checking, code completion, hover-over docs, and linting.
Yes, JSX needs transpilation but that happens at compile-time. Which is better, pre-processing at compile-time, or "transpilation" (i.e., string processing) at run-time?
Updates offered by lit-html appear to be very limited. If you change value of expressions it updates the DOM. What about larger changes, such as list items changing? What about child elements being replaced with new ones?
OK, so plugins can enhance code editing. But what about compile-time checks? With TSX, if you have a mis-matched tag the TypeScript compiler will give you an error.