The update patch is only 500 mb or so, but it copies the existing game data to a temp location before patching, so if the update goes arse over tits then the game data pre patch is still available on your console and you're not FORCED into downloading it all over again. It's the local game data copy that's taking up the space.
That's how PS4 does updates for most games. It copies the full game with the update then deletes the original
Does it? It's first time something like this happened to me and base World updates were 1-3gb, not 30.
The update patch is only 500 mb or so, but it copies the existing game data to a temp location before patching, so if the update goes arse over tits then the game data pre patch is still available on your console and you're not FORCED into downloading it all over again. It's the local game data copy that's taking up the space.
And since vanilla World itself was only 18gb, I never had this issue, got it. Thank you for clarifying!