There's no system that is safe
Even if that is a trading platform with features completely making perfect, a hacker's perspective is always positive. It means that through social engineering even bitcoin could still be hacked and that falls within the responsibility of both the system, affected greatly by the actions of someone owning the assets stored in such platforms.
Disregarding the factors caused by an individual, for me, the safest trading platform are those that having KYC verification. I know that from cryptocurrency space, this mostly hassle, but if imagine if our computer got hacked or our public and private key got stolen, we still have a slight chance or way to claim our funds through proving our identity. Though, this can also serve as a weakness if the exchange itself is taking advantage of the KYC verification eg. Selling information.
