Valid point. And as someone who used XSLT in the browser before 2k heavily it was clear, that this is not the way the web will go. To care not only browser specific rendering and styling behaviour, with browser-based XSLT you also had to track different integrations of libxsl.

But it was fun. One use case was a browsable work package documentation for a big public funded project. The browser native print function rendered the page in a different style with valid page breaks and numbers.