Nobody is safe even the FIAT money I think but for me Bitcoin is more safer than FIAT in terms of robbery, so in short nothing is safe it's just how you can safe it.
Bitcoin is growing very solid and the indicators are showing very soon it's going to the moon. Fiat is old method but bitcoin is more safer and advanced to pay there.
Bitcoin does have redundancy against network attacks due to the distribution of nodes that connects to it; it is virtually impossible for anyone to take down Bitcoin by attacking all the nodes. Bitcoin does prevent against doublespending fairly well and 51% attacks aren't that big of a risk due to the large network hashrates. The address isn't that safe since the ECDSA that derives the public key from the private key can be cracked, revealing the private key. It is not that big of a threat now, however.
For me it's just like this, You will steal My brain, yes you can if you cut it open and bring it to yourself.
But can you steal the knowledge inside my brain? yes but you must have a thing that can do extract that knowledge in My brain, if there is
So again, everything in this world is not safe even the safest place because once you have an idea of it eventually you'll find ways.