>Browsers don't have native support for MathML any more for a good reason. Mozilla did support this for a while but dropped it because of limited adoption and high maintenance burden.
This seems to just be entirely untrue? https://developer.mozilla.org/en-US/docs/Web/MathML shows wide support (For Chromium/Blink-based since version 109) and if I open the example https://developer.mozilla.org/en-US/docs/Web/MathML/Guides/P... in Firefox and Edge both seem to render it correctly.
I assume GP just totally missed that it was added to Chromium 2-3 years ago, thanks to Igalia contributing support for it.
Indeed completely missed that. Of course, the web needs to work on safari and firefox as well. So, it doesn't quite address the core issue here.
AFAIK Safari was the first browser to support MathML fully, and FF also supports it. Chromium was the latest IIRC. MathML has been baseline-available since 2023 after Chromium got support.
The big issue is that MathML is designed as a target language, not something directly writable. So we still need a KaTeX equivalent, which compiles either LaTeX equations or other markup languages to MathML.
Regardless, the core issue that you have mentioned is now gone (or will be in a few years even if you want more availability).
The core issue that Chromium was the one major browser not supporting it? Or what core issue?