Firefox has removed a lot of features, but they view ad blocking as a core selling point for the Firefox product. They've published a handful of blog posts endo

Firefox has removed a lot of features, but they view ad blocking as a core selling point for the Firefox product. They've published a handful of blog posts endorsing specific ad blockers, including AdNauseum, an extension that Google considers to be malware because its purpose is to facilitate the user DoSing Google ad servers. So Mozilla will very likely never leave their implementation of the extensions API deficient for ad blockers. They've laid out exactly what they promise to continue providing in the API, in no uncertain terms.