I would love to use MathML, not directly, but automatically generated from LaTeX, since I find LaTeX much easier to work with than MathML. I mean, while I am writing a mathematical post, I'd much rather write LaTeX (which is almost muscle memory for me), than write MathML (which often tends to get deeply nested and tedious to write). However, the last time I checked, the rendering quality of MathML was quite uneven across browsers, both in terms of aesthetics as well as in terms of accuracy.

For example, if you check the default demo at https://mk12.github.io/web-math-demo/ you'd notice that the contour integral sign has a much larger circle in the MathML rendering (with most default browser fonts) which is quite inconsistent with how contour integrals actually appear in print.

Even if I decide to fix the above problem by loading custom web fonts, there are numerous other edge cases (spacing within subscripts, sizing within subscripts within subscripts, etc.) that need fixing in MathML. At that point, I might as well use full KaTeX. A viable alternative is to have KaTeX or MathJaX generate the HTML and CSS on server-side and send that to the client and that's what I meant by server-side rendering in my earlier comment.