Using the same deposit address repeatedly

As far as I see, coinbase recommends to use a different address for every new deposit. So the preferred way of working is first creating a one time use address and deposit to the address. I think rationale is to prevent tracibility in the block chain explorers. I wonder what happens if we use the same address for all transactions? Currently, we use the same address each time. For instance, if we want to deposit to coinbase from exchange A, we need to add coinbase deposit address as a trusted address and we do not want to do it every time. We are thinking about automating all these workflows and we want to understand the consequences of using the same address for all deposits?