We do not use replication, we use a Reed-Solomon erasure codes, so no copies, each piece is unique. You do not need to keep 80 pieces of the segment to make it unavailable. Holding 52 pieces would be enough to make the segment unavailable. Sometimes even less, because the repair will start when the minimum threshold is passed, so 65-28=37 pieces could be enough.
Numbers are various, depending on used R-S settings, they now can be dynamic. So, numbers above are valid for the default schema: