I think it's a stretch to call firefox on mac "unusable". Like once a month I'll have something not work, and half the time it also doesn't work in chromium (both are the developer's fault). And when it does work in chromium, browsers are free so just switch over there and switch back. And to top it off, there are endless free flavors of chromium like brave etc, that virtually never have compatibility issues without needing to go full google.