Hardware wallet is the best, but if you can't afford it, you can use Electrum Wallet. Electrum is an open source wallet and it's completely free, like your own bank. Never hold on to Coinbase or any other exchange. This is very risky. Electrum wallet is best after hardware wallet.
No doubt about bitcoin mobile wallets, but he was talking about wallet for new projects, even there are plenty of projects that have been operating for year's but don't have any official mobile wallets available for smartphone. I have only 3 mobile wallets for different coins and it really makes it easier to transact.