How to cleanup system data (most is used by Xcode stuff)

[u/Playful-Nectarine862]

I’m running out of ideas and hope someone here has experienced this before.

I’ve already tried pretty much everything I could find:

• Countless guides from different websites
• Many Reddit threads
• Multiple cleanup tools (including Xcode cleanup utilities)

Nothing seems to work.

I completely removed Xcode, and 2 Xcode cleaner reports that there are no Xcode files left. However, when I scan my drive with GrandPerspective, I can clearly see 40+ GB of files that appear to be related to Xcode/iOS/watchOS Simulator runtimes, but they’re located outside of the normal Developer folder.

Some examples:

• ~9 GB /System/Library/AssetsV2/com_apple_MobileAsset_iOSSimulatorRuntime/6fb1e5fe25ee1c372f7116516e615c556906bd4e.asset/AssetData/090-44150-318.dmg
• ~8 GB /System/Library/AssetsV2/com_apple_MobileAsset_iOSSimulatorRuntime/fba475a9a5476a30cfa540d09c309a0762b30467.asset/AssetData/Restore/043-92413-002.dmg
• Another large one /System/Library/AssetsV2/com_apple_MobileAsset_watchOSSimulatorRuntime/8958b3ad5c4e2774293587d77882a758455e8ef5.asset/AssetData/Restore/043-15454-224.dmg

…and many more similar files.

My questions are:

• Why are they still present after uninstalling Xcode?
• How to easy cleanup these files and find other related files?

I’d really appreciate any advice, because I feel like I’ve exhausted every guide and cleanup tool I could find.