If you store coins in online wallets and if the site disappears in a sudden one day, you will lose everything.
Are you scared?
Of course, Are you scared?
but usually i not really save bitcoin in online wallet. I use ledger nano and maybe for ETH tokens, i still use private key to access my wallet. If we still hold private key, we can open it anywhere. But in case we talk about wallet and not exchangers.Nobody, with at least some knowledge about crypto-currencies, would hold coins in some wallet without private keys.
If you don`t have private keys, you don`t own coins. It`s something anyone needs to learn before investing in crypto-currencies.
Mostly, people think about the profit and how to make money, safety is on second or third place. People start to think about the safety
only after they lose coins.