Starting December 14, 2023, extensions marked as Android compatible on addons.mozilla.org (AMO) will be openly available to Firefox for Android users.
“We’ve been so impressed with developer enthusiasm and preparation,” said Giorgio Natili, Firefox Director of Engineering. “Just a few weeks ago it looked like we might have a couple hundred Android extensions for launch, but now we can safely say AMO will have 400+ new Firefox for Android extensions available on December 14. We couldn’t be more thankful to our developer community for embracing this exciting moment.”
In anticipation of the launch of open extensions on Android, we just added a link to “Explore all Android extensions” on AMO’s Android page to make it easy to discover new content. And just for fun and to offer a taste of what’s to come, we also released a couple dozen new open extensions for Android. You can find them listed beneath the Recommended Extensions collection on that AMO Android page. Try a few out!
Definitely, along with the specs of your phone.
Also, with mv3 extensions, the extensions that are not actively doing some work are not really "running" in the first place but are just waiting for some event to happen that they have previously told Firefox to inform them about, but there isn't any persistent execution context that is constantly running.
I believe one reason why extension support was not-fully enabled earlier was because mv2 extensions required persistent background context for each extension and that could cause issues if Android just decided to kill that process. But with mv3 the extensions are required to be able to be suspended and then woken up on demand.