Back with newsgroups the general rule was to go from general to specific. You start with a general discussion group and when discussions about video games get annoying you create a games group. If then there are too many Baldur’s Gate discussions you create BG. If they are dominated by Baldur’s Gate 3 you create a Baldur’s Gate 3 group. If everyone is fawning over Withers you create a Withers group which of course will be flooded with discussion about the Withers’ tits mod, which shall get its own group.
Meaning you should create a group when demand is there and not the other way around.
Somehow !adventuregames@lemm.ee has also absorbed puzzle games there. Not where I’d think to look but okay.
If you made a puzzle game community I’d totally follow and post whenever I see one.
Sadly I do not really engage with video essays because… ugh, video, I’d rather read an article. Shame, because I wish I could say “I’ll engage with this high quality content!” but truth is I have some I reject on personal tastes too. But I promise there are people who will, even if it is only a few. Speaking as someone trucking on with some communities of like… one other person, and I am lucky to have even gotten them because I was screaming at the void for awhile now.