I think nothing to safe in internet, all is have own risk that's is depends by how we use it, already follow the rules to use it? What the risk? And how to minimize the risk and etc.
For example :
• Using harware wallet to keep your ERC20 Tokens, indeed this wallet designed to make your assets safer, easy to use, the ability to make payments quickly, high security, and more. But if we can't learn more how to use that, how to keep it and what we need to more safe (that's like use trusted antivirus), maybe your wallet will be attacked by virus.
• Using Online Wallet like MEW wallet, I'm token and etc that's safe too for your assets, easy to use, fast payment and etc, but you should know how to use it to be safe, seem like keep your private key and keystore it just should you know don't tell anyone,  ingore the fishing, enable 2FA, Google authenticator and etc so thats will be safe. Thank you