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).
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).