Nowadays I highly recommend HTML embedding libraries directly in the programming language. E.g. ScalaTags https://com-lihaoyi.github.io/scalatags/ or (my own) https://github.com/yawaramin/dream-html
Yes, you give up the ability of designers and frontend-only people to easily work with the HTML templates. But in exchange you get quite a lot.
We designed Django (back in ~2003) with the idea that it should be usable by frontend developers who just worked in HTML and CSS, which isn't really a category that exists much today any more.
We used {% %} for tags rather than XML-style partly because we wanted the tags to remain visible in Dreamweaver!