> The lack of support of XSLT 2.0 in browsers is a major issue,

... for who?

XSLT 2.0 is a failed language, only Michael Kay could implement it in the paid version of Saxon and that because he was the editor if the spec, so he did as he pleased.

People stuck with XSLT 1.0 [or worse, javascript] as your tree transformation engine

Yeah, just because browser vendors put XML tech in maintenance mode doesn't mean that it wouldn't be nice to have.

We might see real world usage of these technologies had browser vendors not frozen them out.