When I first heard of Cryptocurrency my friends told me my money would be more secure in crypto than the traditional banks and that I would be my own banker. So I opened a wallet only to hear that some person’s accounts were hacked.
Only if you're under a centralized exchange you can have this kind of encounter or when you left your wallet private keys exposed to other people for your attack, but aside this, you could run a full node, make use of a decentralized cold storage and always have more security measures in practice over your wallet and you can never have such experience.
Hacking a blockchain is nearly impossible,
There are protocols that guide the use of blockchain technology and any input that does not go in consensus with these protocols gets rejected because they are immutable, that alone means no one can alter the protocols except they work in line to conform with them all.