If bitcoin can be robbed like banks or any type of robbery, how can we be safe with this like more tips for security excluding writing key phrase on paper, etc.
100% safe? There is no such thing!
After all Bitcoin or in this case the access to the coins, be it a wallet, a seed phrase, or an encrypted file is still a property that they can get to it or force you to give up, It's a thing of determination and what kind of thieves are you dealing with!
Are you getting mugged in the street and the thief runs with your phone? Simple encryption would help, then you rush home and use your back-up to move the coins to a safe new address! You have 1000
BTC, a gang has found that out, and they are ready to kidnap and torture you? Then, just like any other of your possessions, there is no way of keeping them safe. They will torture you till you give them the keys or they will lose patience and shoot you!
Basically, it's almost the same as other valuables, it's easier to hide from a casual burglar, and you can hide the keys far easier than a 10 square feet painting or a 1 ton of sculpture but if we talk about ransom, that's it.
Probably the best method is to keep your holdings secret, avoid KYC on shady websites so a database leak won't show the whole world your balance and home address, avoid talking and bragging about Bitcoin on social media, and so on, in short, use common sense!