I lurk on Themeparkreview, but I have my own personal issues of how that site is ran and how some members are treated. It was mentioned in a previous thread, but this website really did feel very nonjudgmental and inclusive, and most alternatives (Facebook, Themeparkreview) do not feel that way. I am in a couple of Discord chats which I enjoy and frequent a lot. I use it for the OpenRCT group discussion, my local pinball club, and my friends groupchat. I feel as though Discord would be the most inclusive option, as different channels can be created, and then you can have sub- threads within those channels for discussion on specific topics (such as Rides -> Carousel, or Rollercoasters -> KingdaKa, or 2024 season -> The Flash).
I know Discord was thrown around as an option in a previous thread too, and some people were averse to it, but I honestly don't know what the best alternative is.