You're experience doesn't seem to reflect the majority view here.
There are plenty of active forums around, including some that generate income. There are also many forums that indirectly contribute to a business's income by providing peer support for a product or service. Many organisations use intranet discussion forums to boost communication and collaboration.
Your view is limited. Forums are far from dead and they will prevail in the long term because they provide a unique format compared to other forms of social media and communication in general. But feel free to have a laugh on me