Bank buildings built before 1929 tend to be massive masonry structures with greek columns, marble, etc. Ones build later tend to be cracker boxes in strip malls.

My theory is that the older banks needed to impress their clients with stability, conservativeness, safety, responsibility, etc. After FDIC, customers looked to the government for that, and so banks no longer needed to spend the money on the building.

The massive, glittering vaults are sadly gone now, too. The money exists as data on a server somewhere, little need for a vault.