A valuable lesson can be learned from your friend's father's experience, no matter how much money you have, don't put everything in the same basket. Natural disasters are indeed not easy to predict, but the risk is also very high if they occur in large quantities. Maybe if the person had diversified their assets in different locations their psychology would not have been so shaken, but then again, Bitcoin is more resilient and has a higher level of security when compared to such events.
We should not ignore something that can be profitable in different assets just because we are too confident with the experience we have in the Real estate sector. Bitcoin has proven its resilience and several retail and institutional investors have made Bitcoin a primary investment.
Even if he invests in bitcoin, there is no guarantee that it will save him if the seed phrase is stored in physical form and kept at the site of a natural disaster. As you said, natural disasters are unpredictable and devastating, and Bitcoin is not the god that can save us from them if we store it in physical.
Nothing is absolutely safe, everything has risks and Bitcoin is no exception, even has greater risks. Because online threats are more unpredictable and dangerous.
Majority of cryptocurrency holders and investors store their seed phrases on physical object and no one thinks about a case of natural disaster and the probability of it happen. Since we can't save our seed phrase on the Internet due to the probability of getting hacked, physical storage as being one of the most effective ways to stay from Internet hack or attack. No matter the pattern we choose to save our seed phrase, there will still be disadvantages which is why every alternative we might have might not be safe on all side. All we have to do is to pray that natural disaster should not happen to us so we don't lose everything we have save for all these years.