I once entered a “safe spaces” Discord server with literal flowers and stuff. It looked very innocent and welcoming and it was just for gaming. Turns out, they were making fun of their members on it, fake-crying to mock a depressed user, and kept telling the users to “let them see their cuts”. It was so disturbing. These were literal 18-20 year olds, too, and I was like 13.
In terms of self harm, the only “safe space” that should exist should be one that helps the person get the help they need - and the only kinda space that actually fits that criteria is often the relationship between a trusted stable friend/family member or a therapist. A space with only people struggling will end up as a toxic feedback loop that pulls everyone down.