Coinbase generate a new btc or eth address after every deposit. But how does it send funds from these addresses to another address.
In case of btc, a transaction can have multiple from addresses. But if I have 10,000 addresses and if I want to send all the btc in all those addresses than won't the transactions size become too big and get rejected by the miners maybe.
In case of eth, a transactions cannot be signed by multiple wallets. So if I have 10,000 addresses than I need to create and broadcast 10,000 transactions so the transaction fees will be too high.
How does coinbase.com deal with these problems?