Yeah really...
So your fried has a 10 million balance on Coinbase and has paid the 100 000 $ for it?
Has also your friend understood that this service is not for traders as in trading on exchange but acquiring large sums of crypto, as those are using their funds daily, this is only for businesses that are storing those coins there?
Be honest, in reality you don't have a clue what this service is about, do you?
It's not only that.
In a large corporation or a multinational business it's pretty hard even from legal point of view to entrust the private keys to somebody.
It's like having cash and storing it in the houses of the CEOs.
So, a service like CC which is more like a bank with a secure vault is the easier way to solve problems.