I think it's a better idea to delete mozilla own add-ons and then built it in firefox so that more people will use it. There are add-ons like firefox-translations that haves around 300.000 users because not much people know about it. If mozilla built it into firefox then every user knows about it and it will be then much populaire. They can let it work how it works now but only needs to change a little things like put it out the add-ons section of the browser and make a new place for some of them. They also need to make it available for firefox mobile. Some are not possible for firefox mobile like side view except if you want it on top of each other. The add-ons i'm talking about are: Facebook Container, Firefox Multi-Account Containers, Firefox Translations, Firefox Relay, Firefox Color, Notes by Firefox, Side View, RegretsReporter, Rally Pilot Studies, Extended Color Management and B!tch to Boss. I will link some old posts to look into it. https://connect.mozilla.org/t5/ideas/facebook-container-add-in-but-for-google-sites-and-services/idi... https://connect.mozilla.org/t5/ideas/bring-back-notes-with-sync/idi-p/183 https://connect.mozilla.org/t5/ideas/multi-account-containers-for-android/idi-p/5564 https://connect.mozilla.org/t5/ideas/get-built-in-translation-feature/idi-p/5347
Just because YOU find an add-on useful doesn't mean that I have any use for it! I don't want my Firefox bogged down with add-ons and extensions I have no use for! The whole point of them being add-ons is so that we can customize Firefox to meet our needs. Personally, the only one of those you mentioned that I know of it Regrets Reporter, which I found more annoying (always popping new tabs open) than the YouTube videos it was meant to discover.