Maybe good things will happened next year since @theymos already show a potential reconsideration on mixing ban.
Can you provide where theymos mentioned of this reconsideration? It will really have a big change of the forum's activity if it happen but it means more work for the admins and mods too.
.. The mixer ban in 2023 is not even the main factor because prior to that time, the decline has already started.
That's the most probable reason why it happens, bitcoin price are soaring that time, most of time when bitcoin price is increasing and reaches new ath, forum's activity by posts grows but it decline due to the mixer ban as different users become inactive too.