But what usually happens is that teams tend to be dominated by a talker or extroverted person.

Many people - like A LOT of people - do not do well in chaotic group discussions.

I am not saying there is no place for such forums; but I resist the idea that an Open Space format is the solution for collaboration, or should be a "standard" or "default" approach. To do so is to disempower all of the introverts in the organization - which might be half of its constituents.