Except JSX is being used now all over the place and JSX is basically the return of XHTML! JSX is an XML schema with inline JavaScript.
The difference now days is all in the tooling. It is either precompiled (so the devs see the error) or generated on the backend by a proper library and not someone YOLOing PHP to super glue strings together, as per how dynamic pages were generated in the glory days of XHTML.
We basically got full circle back to XHTML, but with a lot more complications and a worse user experience!