They rewrote the Firefox core, which was definitely good for performance and stability. The change also coincided with the deprecation of XUL addons, which removed a lot of desktop addons as well.
Ever since the rewrite, they’ve kept a small whitelist of addons that usually mostly work. You can make your own list of addons in the settings if you run the beta/nightly version. A lot of addons don’t work, though, because the UI elements that they interact with aren’t available (yet) on mobile.
They rewrote the Firefox core, which was definitely good for performance and stability. The change also coincided with the deprecation of XUL addons, which removed a lot of desktop addons as well.
Ever since the rewrite, they’ve kept a small whitelist of addons that usually mostly work. You can make your own list of addons in the settings if you run the beta/nightly version. A lot of addons don’t work, though, because the UI elements that they interact with aren’t available (yet) on mobile.