What if the central database gets hacked? What if someone does a double-spend? What if the person in charge of the central database decides to redistribute everyone's money or decides to revalue it? What if a transaction fails or someone makes a mistake? How do we know we can trust the owner of said database? What if the central database gets wiped or corrupted?

These are some of the problems with centralization that decentralization solves. The original Satoshi white paper calls out many of these use cases. Part of the reason bitcoin is exploding in value again is because the US government is inflating everyone's money.

This is before even getting into applications of smart contracts...

Congratulations on your successful investment (that's not something I would recommend publicizing though)...