The MathML support in Firefox and Safari are barely usable. Even if my target audience all browsed on Firefox and Safari, I'd avoid MathML.
Parent understood that, that's why they said "Don’t let perfect be the enemy of good".
They mean "It might not work too well, but it works well enough to use".
I may have misunderstood how well it works/doesn’t in Chrome. For right or wrong I understood that MathML didn’t work at all in Chrome.
If there’s some support for a feature, even if it’s ropey, and if there’s no support for that feature in Chrome, then using that feature attacks Chrome. People will have to use other browsers in order to use that feature. They might then continue using that browser.