What would be useful in FF is a content blocker, especially in the mobile version. Not pocket, file sharing apps, voice, notes. There are web apps for that.
Also, uBlock Origin and similar are perfectly functional extensions. Takes just three clicks to install uBlock Origin on a fresh desktop Firefox installation.
If you're wanting to tell me that this content blocker should be default-enabled, good luck explaining to webpage owners that they won't make ad money off of Firefox anymore, but should still support it.