Off-topic threads aren't allowed in the Q&A forum anymore but are welcome in the activity feed. If you ever see any threads that are off-topic within this section, they are likely older ones which were created before the new guidelines were set, or they were merely threads that the moderators had missed.
If you want to ask any off-topic questions or say a general comment or whatnot, the activity feed is the most suitable place for something like that as it was designed to allow users to express themselves with lesser limitations than the Q&A forum
That's why you become an active user and increase your influence.
It's the same as in other places, SO, discourse forums, twitter, etc.
Except influence you aren't limited in any other way.
Even then feed posts are global. You see them from people you do not actually follow.