Deduplication is storing a piece of content once no matter how many times it appears. If forty people commit the same 2 GB asset, a deduplicating store keeps one copy and forty references to it. Content-addressed systems get this naturally, because a file's hash is its identity.
It is a genuine saving, but it optimizes the resource that is cheapest. Storage is inexpensive and getting cheaper. Bandwidth and time are what actually hurt a distributed game team: the artist in another country waiting on a sync before they can start work.
USourceControl stores every version independently, which keeps restore paths simple and makes it impossible for one corrupted shared blob to affect multiple versions. The optimization goes into transfer instead. Every file is hashed with SHA-256, and a sync compares hashes to move only what genuinely changed. Committing a level rebuild that touches forty actors uploads forty files, not the world.
Because storage and bandwidth are unlimited on every plan, the trade has no cost to you. There is no quota where deduplication would have bought headroom.