First of all, CDs, DVDs, Blue-Ray discs, and M-discs are becoming old technology. Very few computers come with optical drives that can handle any of them anymore. That really leaves only three up-to-date choices: 1) cloud storage, (like, Dropbox, iCloud, Microsoft's OneDrive, GoogleDrive, etc.) 2) flash drives, or 3) external hard drives.
1) The best option for cloud storage is FamilySearch in their Memories section. The only drawback to that is that the files are limited to 15 MB. That is fine for pictures and histories, if the histories are compressed and posted as PDFs. That is too small for lengthy recorded interviews and similar large audio files. I am ignoring the other cloud storage options because the data is saved only as long as the account is financially active. They are great for temporary storage, but not for long-term archival storage.
2) Flash drives are great in that they are very portable. The drawback to them is that they are small enough that they can be more easily lost. They used to be limited in size, but relatively larger sizes are now available at reasonable costs. The big advantage to them is that you can more inexpensively make several copies for everyone in the family. Personally, I think I would, and will for future projects keep the original files on the hard drive of my computer. put those same files on flash drives, and make a complete back-up on an external hard drive.
3) External hard drives come in two different kinds, HDDs that are older technology with spinning platters, and SSDs that are really just very big flash drives. There is a really good article comparing them (although it is a little dated now) at: https://www.crucial.com/articles/about-ssd/ssd-vs-hdd
By the way Crucial is a Micron company, so Crucial and Lexar products are both made by Micron.
My personal experience has been that drives made by Micron, Western Digital (WD), or Seagate are top quality external drives.
For reviews of external drives see the following: https://pcgearlab.com/ click on the "guides" menu at the top of the page. Scroll down to "Storages". There are three articles that address the topic. Also see: https://www.techradar.com/news/best-external-desktop-and-portable-hard-disk-drives
For comparisons of flash drives see the following articles: https://www.securedatarecovery.com/blog/is-a-usb-flash-drive-more-reliable-than-a-hard-drive-2
https://www.tomsguide.com/best-picks/best-usb-drives
https://www.techradar.com/news/best-usb-flash-drives
For further research you can do a Google search for most durable flash drives, but they are for things like military use, etc. The bottom line is that the best flash drives recommended by the sites above change from year to year. Not flash drive lasts forever, therefore they need to be backed up periodically.
One last thought, a retired Church History employee has said that the best way to preserve these photos, histories, and documents is to make multiple copies and get them into the hands of as many people as possible. Therefore, it is probably best to use more than one of the storage options discussed here, and give copies to family members.
The only really durable permanent storage solution for data of any kind is on gold plates. Frankly, we haven't made much progress since the days of Moroni. ; - )
The opinions expressed in this article are strictly my own--plus the opinions of the authors on their respective web sites.