Yes, but those workarounds will be author-side ones. Like how HTML isn't very friendly to write by hand for many, so CMSes use e.g. Markdown or WYSIWYG to make it friendlier. In the same way, there will always be preprocessors in authoring tools that might convert e.g. TeX notation to MathML.

My point is that "fast" in those kinds of workarounds wouldn't be a problem for visitors of a site because all the browser gets is just native MathML.