@tiox, i definitely agree about SD cards not being a great long-term medium. But there are questions like “long-term medium for what?”, and “how long is long-term?”. I think there are no long-term data storage mediums that are all that good.
I came to linux because the spinny-disk of the last Windows laptop i owned died. Starting with that one (including it), i’ve lost 2 HDD’s, one SSD, 3 or 4 microsd’s, and probably dozens of USB sticks. Lots and lots less than the number of floppy-disks i’ve pitched, but still more than i would prefer.
What i’ve concluded, given what little i know about the current hardware technology, is the following, fwiw. They use the same technology to make the memory chips in USB sticks, microsd cards, and SSD’s, and for a company that makes all three, it’s a matter of QC sorting the chips down near the end of the manufacturing line. The obviously bad ones get pitched. The acceptable ones go into USB sticks, better ones go into microsd cards, and the best of the bunch go into SSD’s.
Now, maybe i’m mistaken about that, i haven’t set foot inside a chip fab facility since i went on a tour of AMD’s place (in Cupertino or thereabouts as i recall) the '70s. The point is, the technology is continuing to develop. You can buy a 1TB SSD for $275 these days. You can buy a 200GB microsd card for $75. For the types of apps i’m most familiar with (i’m not a gamer) performance is going to be good enough. It should be about the same as the performance of the nearly-identical chip that’s wired into your latest tablet or your phone.
I’m a practical guy, i look at these 1TB devices, and i think, outside of a server, what would you store on these things? Movies and music, probably. I run all my distros in 10G partitions and haven’t run out of space since i moved to that policy. All of my source code is probably… 5Gb i’m guessing. This xps13 has a 250GB SSD in it, including 50GB of archives and tar backups, 8 bootable distros, 4 swap partitions at 8GB each, and miscellaneous, with 20GB still not even partitioned. I probably have around 3GB of photos in the mix. I got a good deal on an 850GB SSD a while back and put it in my wife’s machine where it’s virtually unused.
Okay, so we have random failures in all devices because that’s how manufacturing processes work, we know this already. But failure rates are down and processes are continuting to improve, so extrapolating that, along with the fact that they either are, or soon will be, using 3D printing or equivalent, instead of going the photo-etching “growing” approach (if they didn’t abandon it for 2D printing years ago), what you get to is absolutely humongous storage capabilities for nearly no cost but with some infinitesimal but real failure rate.
Finally the point, what are you gonna do when your 1TB SSD fails, wait several days for dd to move every byte from the backup it was too much trouble to make?
I guess what i’ve taken a long time to express is that sooner or later any “long-term medium” is going to give out on you no matter how good it is. The fact that a microsd card will almost certainly give out before your vinyl recordings lose their playability unless the dog gets to them, that’s true, but with things going in the direction they’re going, i think it’s more important to have a rugged backup strategy than it is to marry yourself to a perfect hard-drive, because sooner or later Murphy’ll be around to visit, and you’re gonna want those backups.
If performance and reliability are matched to usage, i don’t think it matters what the media is. When one of my USB sticks went bad, i tossed it and set up another one. Same deal these days with microsd cards, when one goes bad i pitch it and set up another one. It’s a mortal PITA but it does come around once in a while.
Backup strategies. Small partitions. Independent recoverability. Without being dependent on some cloud when the internet is under attack through the power grid, or in my case when the local cell-tower is unavailable due to local weather.
Sorry for preaching my sermon, it seems to be what i do when i’m not trying to remember how that next piece of code is going to work once it’s written; i prolly should do more of that and less of this, but it is so much easier to talk about it than it is do it, until you’re actually doing it, when the rest of it disappears. 
