> I have yet to read an article complaining about XSLT deprecation from someone who can explain why they actually used it and why it’s important to them.

I used it to develop a website because I'm not a programmer, but I still want to have some basic templates on my webpage without having to set up a dev environment or a static site generator. XML and XSLT extend HTML _just enough_ to let me do some fun things without me having to become a full-on programmer.