I would have to disagree, remember Satoshis white paper...
"A purely peer-to-peer version of electronic cash would allow online payments to be sent directly from one party to another without going through a financial institution".
Many people tend to forget the importance of Peer-to-peer but I do understand that coinbase is the fastest and most convinent way to acquire crypto.
I just want to emphasize that if you don't have to use a third party financial institution (like Coinbase) then DONT. If you can buy BTC, BCH or LTC from a friend or someone you trust with cash then that would be the ideal thing to do. Just my opinion.