I watch a YouTube channel called Never Too Small and they have Singapore apartment designed by a father for his son. It's an amazing apartment, I couldn't live in it but it fits its owner perfectly. What caught my attention was that it had a bomb shelter in it, so I looked it up and it turns out that every home built since 1997 is required to have one.
A bit of Googling shows that everyone uses it for storage and very few have any confidence that it would stay standing 14 stories up if a building was bombed, although in theory it should as they are stacked on top of each other and reinforced and should still be there even if the rest of the building collapses.
I can't really find any reason why they require this. Some conspiracy type theories are that it's to make citizens a bit scared and therefore more likely to obey the government. I could understand why somewhere like Taiwan would require it as they are perpetually under threat of invasion by China, but Singapore doesn't have any countries making territorial claims on it.