Technically, that magnetic spinning HDD can work even after decades if maintained safely (no dust, no extreme heat) and without stress, even if it is not switched on for years.

In fact, if a magnetic HDD crashes, you may still recover some or all of the data by doing something hardcore, such as letting it sit for some hours in the freezer of your refrigerator, or immersing it in a bowl of rice overnight.

However, SSDs (and other flash storage devices) need to be switched on once in few months, otherwise there's a chance that some data stored in them may be permanently lost, as some cells may loose their power.

"As a reminder, an SSD's endurance rating is calculated based on how long it can store data if left unplugged after a certain amount of data has been written": https://www.tomshardware.com/pc-components/storage/unpowered...

Spinning rust may be defeated by Janet Jackson, but your chip storage is defeated by just sitting undisturbed in a drawer or a closet for too long...

It's a reason not to use a hard drive from over 20 years ago.

But if you're stuck with hardware that old, an SSD isn't an option.

Platters are not made of iron (or even steel) and neither is the surface, so I’m not sure why rust comes into the picture.