You could get extensions working on FF for Android, for some time now, by setting a custom collection ID, allowed in the Beta version.
The problem is that many extensions have been incompatible with Android. And of those compatible, many have poor UX. For example, LeechBlock has been compatible and listed as available for some time, but its settings page isn't mobile-friendly. And LeechBlock can't restore settings from “sync storage”, you have to load them from a local file (on mobile, having local files is a challenge in itself). Many people may have a bad experience.
On the other hand, extensions are the primary reason to use Firefox on Android. Therefore, I'm glad about this news.
The problem is that many extensions have been incompatible with Android. And of those compatible, many have poor UX. For example, LeechBlock has been compatible and listed as available for some time, but its settings page isn't mobile-friendly. And LeechBlock can't restore settings from “sync storage”, you have to load them from a local file (on mobile, having local files is a challenge in itself). Many people may have a bad experience.
On the other hand, extensions are the primary reason to use Firefox on Android. Therefore, I'm glad about this news.