My shocker for the day was finding out that SSD drives start to lose data when they are powered off. It depends on the environmental conditions but, worst case, an unpowered SSD drive will start to lose data in a week.
The big takeaway for me on this is to not use SSD drives as external USB drives. I have an SSD drive in an external enclosure that emulates an optical drive based on ISOs stored on the drive. I use this every once in a while, but could conceivably go for several months without using it. During this extended period without being powered up, it could lose data.
So, if you're archiving data on external drives for an extended period of time make it a traditional spinning disk.