Personally, there are some smaller communities that exist on Reddit that just don’t exist on Lemmy, or have inactive communities. The other option for some of those communities is Twitter, so I’d much rather just check Reddit. I also don’t expect my local towns subreddit to move to Lemmy from Reddit. I think it’s less about returning to Reddit and more so wanting to participate in small communities that exist in Reddit.
Generally you are not distributing any content from the game. Most mods to games are using API calls to a mod loader to change the game for the user on runtime. These distributed mods generally have no copyright content in them.