Tuhi, your storage assistant · What Tuhi knows
Why does Tuhi say moving big apps needs a fast external drive?
Short answer: Moves need somewhere to put things, so they need a fast external drive set up in Storage Studio. Without one you can still clear caches, reclaim old local backups and keep cloud files online-only.
Moving large apps and folders off your Mac needs somewhere to put them, so those suggestions need a fast external drive connected and set up in Storage Studio. Tuhi says so rather than offering a move that can't happen.
Without a drive you can still clear caches and rarely-used files, reclaim old local backups and keep cloud files online-only. Connect a drive later and the moving options appear. See external drives.