The biggest problem of crypto is that you can easily lose your coins. Like forgetting your key, getting scammed and sending to the wrong address. If you have one of these problem than it is difficult to get your coins back. You cannot contact someone and ask them to stop the transaction/refund, if you had a bank account then it would be possible.
true if it happens like losing private keys, fraud and wrong sending address will be the biggest problem but if we are not careless and always guard with secrets it will certainly be safe.