I hold my bitcoins online at Coinbase. Even seems not secure in the first view this is only an impression and not a fact. Seems that the online wallet are the less secure but if read all the data given about this matter offered by Coin base understand the right meaning that the word "secure" has for this business. I am writing some. First must be told (even this has nothing to do with the security but with your pocket) all the fee-s of the sent of bitcoin are paid from Coin base.
Honestly, I advise you should to use other online wallet instead of Coinbase. Although Coinbase wallet has not about security our money, but when you need to withdraw your Bitcoin when Bitcoin has strong volatility in the market, that is the time you usually can not withdraw your money and pending until the price of Bitcoin stable. It is just my experience used this wallet in one year, therefore I do not know this wallet has solve this issue or not, but I think my said can help you consider.
But you didn't really offer him what to replace Coinbase with. It's like saying not to drink water but didn't say what type of other liquid should he drink. Should he drink soda, pepsi, coke? None of that information. I suggest that you find a local online wallet. In my case, the local online wallet uses the exchange rate at the time that you requested cash out. Once you've issued a cash out, the wallet is just waiting for you to pay. It does have an expiration though. I think this is to prevent having people have multiple cash out and cash in requests and use those to trade funds whenever a spike is happening and make profit just by that little loophole.
In case you want to actually be "secure", you should use a desktop wallet or an offline wallet. Coinbase is on the Internet and it's no brainer that hackers are going to try to put it down and gather all the coins that coinbase has. Once that happens, you cannot do anything because it's not coinbase's fault that they got attacked so much and with the amount of coins that's in their system, they are never going to be able to pay all that.
I agree with you but i do not trust desktop wallets but an offline wallets seems very good because if you use that no one can enter it with the internet so no hacker would be able to reach your wallet but i use blockchain en mew for my altcoins.