Most banks don't have real vaults anymore unless they have safe deposit boxes and those are weak sauce.
Back when bearer bonds were a thing and people had to clip coupons to collect their dividends banks used to have massive safe deposit vaults because it was the only safe place to store those bonds. The real money stored in banks was never cash, bullion, or precious stones, but all those coupons.
When you think of all the manual accounting & filing labor, plus having to meet in person for various transactions/consultations, getting money for the week, making deposits, and all the time it took to clip and store coupons, that's why bank buildings used to be massive edifices. Now almost all of that is obsolete.