Peter Krautzberger, maintainer of MathJax, apparently thinks that MathML has failed as a web standard (even though it succeeded as an XML standard), and should be removed from HTML5. Here's the link:

https://www.peterkrautzberger.org/0186/

It's quite a rant. Here's a quick TL;DR:

It doesn’t matter whether or not MathML is a good XML language. Personally, I think it’s quite alright. It’s also clearly a success in the XML publishing world, serving an important role in standards such as JATS and BITS.

The problem is: MathML has failed on the web.

Not a single browser vendor has stated an intent to work on the code, not a single browser developer has been seen on the MathWG. After 18 years, not a single browser vendor is willing to dedicate even a small percentage of a developer to MathML.

Math layout can and should be done in CSS and SVG. Let’s improve them incrementally to make it simpler.

It’s possible to generate HTML+CSS or SVG that renders any MathML content – on the server, mind you, no client-side JS required (but of course possible).

Since layout is practically solved (or at least achievable), we really need to solve the semantics. Presentation MathML is not sufficient, Content MathML is just not relevant.

We need to look where the web handles semantics today – that’s ARIA and HTML but also microdata, rdfa etc.

I think both, the rendering as well as the semantics, are well worth thinking about. Perhaps Wikimedia should reach out to Peter Krautzberger, and discuss some ideas of how math (and physics, and chemistry) content should be handled by Wikipedia, Wikidata, and friends. This seems like a cross roads, and we should have a hand in where things are going from here.

-- daniel (not a MathML expert all all)