Discord has supplanted them but it provides a far inferior experience compared to a forum.

To give a personal anecdote, I was trying to follow BlenderGuru’s donut tutorial, and was stuck on something or other. Of course, BlenderGuru has a Discord, and there’s a channel specifically for questions about his donut tutorial. I ask my question, and it flies off the top of the screen like a barrel going over Niagara Falls, never to be seen again.

Since you don’t specify what game, I’m assuming you’re looking to start a general gaming forum. That’s probably a smarter bet than dedicating a forum to a single game, and so a much smaller pool of potential forum members. Most people may need some convincing to join a traditional forum after years of Reddit, Discord, and Facebook. You could perhaps lean into the traditional forum angle, trying to attract people nostalgic for slower, more long lasting, and personal style of communication offered by forums.

If you have the admin skills and don’t expect a lot of concurrent users, a VPS is cheap, so the risk is low. I’d say go for it anyway.