What is the Hardest Part of Running a Forum

I have been running forums for almost 9 years. Based on my personal experience, the hardest part of running a forum is getting regular posters. If you do promotion, you can easily get users but it is really difficult to get them to post regularly on your forum. It is also very difficult to get quality posters.
What is the hardest part of running a forum for you?

Yes, recurring posters are hard to obtain in today's forum universe. My board gets decent registrations and log-ins, but sometimes it goes a day or two with no posts. I own a resource board where people mainly come for resources and leave, but I also have a variety of discussion forums. Having the patience to find success for your forum can also be complicated.

Patience is the key when it comes to running a forum, but the question is how long? I have been running a forum since 6 years and it does not even have 100 members, even though I get daily activities.

The cost and time of it all, and knowing what knowledge

Honestly getting members and getting them to post. Post exchanges are probably the best way to get members other than organic growth. It's possible but much more difficult to get members. Though if you have a specific niche it might do better on a forum than on other platforms. I know of a forum that talks about a controversial topic that was banned from Reddit so it moved to a forum and it has many active members on it.

People think running forum is just opening a site and letting members talk. That's not true at all. One argument between two stubborn users can cause commotion in the whole thread. I was literally dealing with something like that last month where two guys turned a small debate into personal insults. That for me is a big headache.

I believe it's building a thriving community with steady activity. This is a very big challenge for most forums. It's not easy these days to find pure forum lovers because social media platforms have ruined everything.

I think that the cost of running a forum could be a really hard thing to manage. Apart from that, maintaining a forum is not that easy either. Regardless of that, there are many people who have been running forums quite successfully.