True - but be very careful. Roughly 10–18% of all BTC are believed gone forever due to lost keys/wallets. That is more than all hacks and exchange blowups combined. If you take your wallet offline it can be hard not to lose your keys over a long period of time, including across death to your next of kin.
Coinbase is good for on-ramping, bad for storage. You know, the entire point of cryptocurrency.