It's encouraging to see browsers actually deprecate APIs, when I think a lot of problems with the Web and Web security in particular is people start using new technologies too fast but don't stop using old ones fast enough.

That said, it's also pretty sad. I remember back in the 2000s writing purely XML websites with stylesheets for display, and XML+XSLT is more powerful, more rigorous, and arguably more performant now in the average case than JSON + React + vast amounts of random collated libraries which has become the Web "standard".

But I guess LLMs aren't great at generating XSLT, so it's unlikely to gain back that market in the near future. It was a good standard (though not without flaws), I hope the people who designed it are still proud of the influence it did have.