Spot on question! Yes, absolutely. Centralized exchanges (CEXs) always charge a flat withdrawal fee to cover the network's gas/blockchain fees plus their own processing costs. For Ethereum (ETH), this fee can vary significantly depending on network congestion, while for Bitcoin (BTC), it is typically a set amount.
It's usually worth moving your funds in larger batches to make the fee fractional compared to your total balance. You can always check the exchange's "Fee Schedule" page before initiating the transfer to avoid surprises.