Data Stick, Memory Card, DVD, Hard Drive or ??????
This is for storage of pictures, videos, and Documents. Is one safer then another or longer lasting? The memory cards and data sticks are small and easy to store.
Multiple copies on multiple mediums. Period.
A good DVD or BD will last several years with good storage. An HDD might. A flash drive might. But if the storage environment is compromised, or not climate-controlled to begin with, then it's a roll of the dice.
A DVD or BD can degrade from temp or sunlight, or lose its seal. It will degrade from age regardless.
An HDD may have sectors which are worse than others. The magnetic field won't weaken with a good sector much over the course of years, but the whole surface of the platter can vary. I've experienced bit rot with healthy HDDs, on backups verified before being stored. Also, a stored HDDs could suffer mechanical maladies, as lube settles over long periods, and possibly hardens, depending on what they use.
A USB drive, SD card, etc., may have any variety of NAND types and qualities (could be top-bin 5k p/e MLC, or bottom-of-the-barrel 500 p/e TLC). As you use it, it wears, but you have no way to know how worn it is, and you don't know how well it handles aging. You could lose data by bad blocks developing, or sectors too worn out, and you just don't know. Over-provisioning tends to be minimal, and writes are synchronized, so you'll likely get much worse WA than a SATA SSD, unless it's only giant files like photos and videos.
That's not to say a given USB stick or HDD won't keep your data intact for 20 years. Just that you can't be certain enough of that to trust it.
Nothing beats multiple copies, the more the better, and managing those multiple copies over time, regardless of medium.