Forum Discussion
Enabling Mods in-game is irrelevant, it doesn't touch the Tray folder. You need to separate them from one another in your understanding.
The game will only ever look in your Documents folder for an Electronic Arts > The Sims 4 folder to load user data from, if you don't have the user data folder there (you stated you have one in /Users/daniel/The Sims 4) it won't be read and a new folder will be created. Yours is currently in iCloud which is fine until your internal storage fills up and iCloud decides to push files to the cloud, see this guide [READ FIRST] Saves, CC/Mods or Library items disappeared? iCloud issues | EA Forums - 10979712
You say Tray Importer has confirmed the files are valid but won't that just be a logic check? Maybe the files are incomplete or damaged from the creator? Tray Importer has been known to be buggy in macOS too.