You can not say cryptocurrency is safe and secure unless you point to some particular coins or tokens. There have been many scam projects and pump and dump projects. Some coins remain shit and become of no value. All these makes many cryptocurrencies not to be secure. It s not only when they are safe in your wallet that you will say they are safe, you have to talk about the whole project of a coin and token and how successful it is.
Bitcoin is the only reliable cryptocurrency at the moment. What else do you expect it to prove after the previous bull run and the upcoming bul run . Look at the way Bitcoin gradually show its uniqueness it is nothing compared to other cryptocurrency