If you have a fear of rollercoasters, then living in the Harry Potter universe will mean hiding your Galleons and Sickles in a jar under your bed, as taking a ride on the unpredictable tracks in Gringotts is one of the many security measures taken by the goblins who run the place. It's not exactly as simple as going to an ATM. The bank also has a waterfall designed to remove any charms or spells, and vicious dragons walking around who are trained to devour anyone trying to break in, which isn't recommended. Even if one manages to break into the building and get to a vault, only a goblin can open its doors, and once inside, any valuable items are likely protected by spells such as the Geminio curse.
It might sound like the best place to store your money, but goblins aren't exactly trustworthy creatures, and they're far from fans of witches and wizards. In fact, the Goblin Rebellions went on for centuries due to discrimination against them and attempts to enslave them like house elves. Wizards have even taken away their rights to use a wand, which has been thought to be one of the main reasons goblins continue to revolt. Some might think it's not exactly smart to let your enemies have total control over your money, but the wizards attempted and failed to take over Gringotts, so living in the wizarding world will likely mean you'll have to figure out how to break into your own vault one day.