What’s a better way to store votes?
versus 
Safes
Safes are good places to keep money, because money, like mushrooms, grows in the dark. Safes are not good places to keep things that require light, like votes and houseplants.
When you put money in a safe, your concern is that the money be there when you open it. The bank that owns the safe has the same objective. You probably do not want the safe to have a readout that displays it’s contents to arbitrary members of the public.
You trust your bank, your bank trusts you (although they often should do more to be sure it is you, not someone stealing your identity) and it all works out. The bank staff knows how to operate the safe correctly, since they do it every day, and the safe is guarded at night by people who don’t know how to open it.
Ballot Boxes
As discussed before, a ballot box has different and greater security requirements.
A ballot box collects votes, not money. Votes, or more precisely ballot images, are not fungible like money - they are multidimensional, multivalued data elements rather than scalar units with a denomination. For example, my vote yesterday included the primary candidate for president (pick one), primary candidate for representative (pick one), circuit court judge (pick no more than two from a list of two), female delegates to the national convention (vote for no more than four), and male delegates to the national convention (vote for no more than four).
(How common is it to vote for delegates by gender btw?)
A ballot box must make information about it’s contents public. It should display how many votes have been cast, and should allow auditors to determine that votes have not been altered at any point.
Update
After watching the video in the post above, I realize that I overstated the case. A ballot box much make some information about it’s contents public, e.g. number of votes and the current validity status of each vote. The vote choice or ballot image must not be visible at all times, but only at the end of the process when it’s tallying time.