There’s some difference.
So you have the slang that’s akin to “Rad”. Words used with sincerity to communicate. “Rizz” and “Sus” fall into this category and seem pretty ‘mundane’, shortening Charisma and Suspicious.
Skibidi is a bit different. It’s more like that generations “Wazzzzzzzuuuuuuuup?” It’s something they themselves consider “just stupid to say”.
Didn’t say that the concept of absurdist G-Mod stuff is new, it’s that the singular specific “skibidi toilet” thing is new.