It seems like a lot of the stories on both wikis are in-universe dark-fics. I don't like to be snobbish about what is and isn't "creepypasta", but to me in-universe dark-fics can barely be considered a creepypasta thing since dark fanfiction is something that existed before the rise of creepypasta.
As for the out-of-universe stories, they seem to just be run-of-the-mill "weird glitch" creepypastas.
I don't get the appeal of these communities to be honest. In theory I guess I could see the appeal of a community that caters to people who like both Minecraft and creepypasta to discuss both, with creepypasta content alongside Minecraft content, but that's not what MCCPW is, it's a place where people generally only write and read Minecraft creepypastas. Creepypasta may be trite as is but at least most creepypasta communities don't have 2000 stories about the exact same thing. But at least MCCPW allows stories not related to Minecraft, whereas RCPW only allows Roblox stories.
The thing that made Pokemon creepypastas popular is that the authors generally at least tried to make the stories able to appeal to someone who has never played Pokemon before. I have not observed that with stories on MCCPW and RCPW. They are virtually all written to only appeal to members of their own wiki community. The stories are too inside baseball to be enjoyable for anyone who ins't really into Minecraft or Roblox, and even if you are into those games I can't imagine wanting to read or write more than a few horror stories about them.
Beyond that, my lurking observation of both wikis has shown them to be poorly managed at best. The wikis aren't as utterly dysfunctional as they used to be just a couple years ago, but they are still hardly models of how to run a wiki community. The Great Mandroid Event of 2018 happened because RCPW thought it was a good idea to have 20 bureaucrats, just a couple months after the exact same thing happened on Geoshea's Lost Episodes Wiki with their 40-something bureaucrats. And it's only been a couple years since MCCPW had their official "wars" and "public enemies" until one of our own users from this wiki become an admin there and convinced them to cut it out because it was making their wiki look stupid.
Personally I want to know why pastas are so popular with those two demographics. They all read pretty much the exact same way, so I find it hard to imagine an audience thats almost exclusively made of kids wouldn't get bored of that eventually.
I think the audience for Minecraft and Roblox fiction is no older than 13, which is not a bad market to be in. There is a lot of potential in children's fiction.
The possibilities are limitless, given that both Minecraft and Roblox are creative sandboxes driven by imagination. Minecraft in particular has a certain horror vibe to it. I have little experience or interest with Roblox, since everything I've seen related to it just seems absolutely garbage-tier.
Writing fan-fiction is a good stepping stone to writing in general. You'll learn a lot as you write, and eventually you'll want to branch out.
Did you know that one of the best-selling novel trilogies of all time was a Twilight fan-fiction?
Max Brooks, son of legendary filmmaker Mel Brooks, and author of World War Z has written a Minecraft novel. If that doesn't tell you the viability and appeal of writing Minecraft fan-fiction, I don't know what does.
In short, yes. Write your stories. Don't stop. Just don't post them here, they will be deleted.